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Topic 1: severe accidents

Henry Tan's picture

Safety Engineering and Risk Management Debate 2012

Discussion Topic 1: Rank top ten severe accidents in energy sector

Rank top ten severe accidents in energy sector, and investigates their causes and consequences. Discuss the following:
 (1)    What were the physical/technical circumstances that led to the accident?
 (2)    What were the main underlying causes?
 (3)    Why did the accident result in: (i) So many fatalities; (ii) So much harm to the environment etc.?
 (4)    What factors contributed to the escalation of the accident?
 (5)    What were the legal consequences of the accident? 


leighmoreton's picture


The Paul Scherrer Institut(PSI) developed a database in 1998 which stores records for accidents occuring in the energy industry.  This database is called the Energy Related Severe Accident Database (ENSAD), It cover accidents and incidents recorded in the fossil fuel, hydropower and nuclear energy insustries.  These incidents are not just limited to the power plants for the energy chains, later development of the database allowed companies to have access to incidents reported in their chain, a view of the costs incurred in the accident and is used to aid companies in development of their safety policies.

The Database has a list of 7 criteria which classify an accident as severe.  Only one criteria is needed to be met in order to make the accident meet the classification of a severe accident. 
These criteria are:
 1. There must be at least 5 deaths
 2. There must be at least 10 injuries
 3. The accident results in at least 200 evacuees
 4. There must be a large scale food consumpiton ban
 5. There is a release of hydrocarbons, over 10,000 Tonnes
 6. The company is placed under and enforced clear-up of the land or surrounding environment
 7. The company makes an economic loss of at least $5 Million (USD)

This database however is not the only method of storing a record of serious accidents which occur in the energy industry.  There are also; the casualties and demolition database, minerals management service accident database, acute hazardous events database, SONATA, the VARO database, OSH-ROM, HSELINE, NIOSHTIC, CISDOC and the ETDE energy database are just a few.

Following the definition of a severe accident I would like to suggest that the Aberfan Colliery Disaster is a suitable candidate for being on of the top 10 disasters in the energy industry as I feel that it fits into more then one of the criteria illustrated above.  I will discuss the Aberfan Disaster in my next post.

Leigh Moreton
MSc Renewable Energy

Aaron McKenna's picture

I wish to continue Leigh’s post regarding severity of an
accident and how it is quantified according to current databases. After reading
this, it made me re-think the situation of the Valero Refinery fire (for which
I made a post on earlier today in the original forum section). In this incident
only 3 people were injured. However, after analyzing the incident it was
discovered that had the circumstances been slightly different a much higher
number of casualties and perhaps fatalities would have occurred. For such an
incident, according to the criteria outlined by Leigh, this would have not been
considered a severe accident. Obviously, there were fundamental failures in the
facility that led to the accident, which as discussed may have caused a lot
more damage than they did in reality. Does this mean we treat this incident any
differently from one in which there were many losses of life? Surely the
lessons to be learnt apply all the same, whether it is “severe” or not? This
then also brings into question why we have to quantify “severity”. Will it lead
to a different response from investigations, consequent legislation etc.? These
are just thoughts that maybe worth discussing.

Tony Morgan's picture

This is an excellent point that i'd like to take further........

The simple answer is YES there is a general liklehood that anything which falls outwith the criteria for SEVERITY employed by organisations then this will likely result in less focus.

This is WRONG. The same focus/ resources should be applied based upon the POTENTIAL SEVERITY since this is the reality that it could be simply luck that has resulted in the low severity as can be seen with many of the posts on the timing of accidents occurring.

Some industries / organisations have taken steps to address this issue.....many have not!!!

Near miss incidents are really gifts to organisations and must be seen as opportunities to learn the lessons before it happens.

This MUST be the pro-active type of safety culture required globally. PREVENTATIVE measures however small can only lead to improvement.

As shown by ref below i'm proud to say that the UK Oil and Gas industry has taken a lead on this type of work by use of HIPO ( high potential incident) safety alert systems and campaigns individual organisations or industry orgs such as directly below.

The Safety Philosophy behind Near Miss Incidents - CRCnetBASE

tony morgan

MSc Subsea Engineering

leighmoreton's picture

I do agree here with you Aaron, if your incident had occured under different circumstances then the consequences could have turned out a lot worse. I personally feel that any accident in the work place which results in any number of fatalities is not acceptable, especially when they could have been avoided.  I have just read on a webpage that in 2010 a refinery explosion in America resulted in the deaths of 6 people and was caused by 'willfull' saftey violations from the company, I will go into detail in abother post about this incident.

In my opinion anywhere where we can learn from mistakes and generate a safer working environment is worth documenting, no matter the 'Severity'.  I just believes that for this post it may have been useful to have guidelines as to what industries consider as a 'severe accident' and the above information is what I found as a result.

I still seem to be having problems with posting comments so apologies if this appears blank 

Leigh Moreton
MSc Renewable Energy

Ahmed_Abdelkhalek's picture

Building on Leigh’s post, the overall severity of an
accident is the sum of the effects on;

People (number of
fatalities , number of injuries, number of evacuees)

Environment (Effect on
living organisms, Food contamination, etc.)


My proposition – As pragmatic as it may seem – is to quantify
the severity of an accident in terms of financial losses. I understand and
totally agree that human life is un-priced and I totally agree with that, but
come to the real life it is “quantified” in the form of compensations.

I also propose that we form a group in which we all pitch in
and try to rank the top 10 accidents according to an agreed upon methodology in
order to make use of this discussion. Anybody interested?

The way is see it;

We search the internet for the
total costs of the accident (Either direct or long term)

This cost should include;

Asset losses

Profit losses

Compensations paid to people affected by the

Yaw Akyampon Boakye-Ansah's picture

have reviewed the classification you have outlined here as the reasons behind
ranking an accident as severe or not. I am of the opinion that any one of these
should be the basis for ranking an accident as severe or not as stated in the article. Although this is explicit, the report is not exhaustive. My convictions
are based on the fact that the point raised here seem to be upheld for:

  • Companies with a large workforce where at least 5 or 10
    people are exposed to those conditions that are likely to be considered
    hazardous or risky.
  • The event of having more than 200people present at the
    time of the accident and who also managed to survive.
  • Events where there are likely to be spillages,
    hazardous effluents and gaseous evolutions which cannot be contained.
  • Hydrocarbons are released in the atmosphere as by the
    standard of the measurement, the volume should allow the accident to occur
    in a large enough locality.
  • Events where extreme amounts of money are lost.

these convictions are right in a sense for severe
cases, this would limit the number of accidents that can be classified as less
severe or otherwise.

I presume the accident in question has to be evaluated according to the
economic strength of the companies or organisations involved or otherwise.
Depending on this factor, a company can be considered to have suffered severe
accident if certain percentage of their workforce is lost. A fatal loss of 2
out of 4 workers is 50% of the workers lost and that can be damaging to any
company's reputation. The FAR value will be 26041.67 per 1x10^8 man hours. If
the other 2 workers were seriously injured, that would give the same value for
SIR. The IR will be 0.5 and the AFR for one year will be 2. This will be in
stark contrast to another company which may be providing the same services
whose work force may be more, let's say 300. If there are 7 fatalities and 15
injuries, the FAR=1215.28 per 1x10^8man hours, SIR= 2604.17 per 1x10^8man hours
and so on. 100 fatalities in a 50000 workforce will present significantly lower
evaluations. On paper, the higher human loss for the second company does not
look too bad statistically. Thus, numbers and statistics should be used
together to really express the situation on the ground.

some accidents may occur which do not necessarily lead to evacuation of the
personnel. If an accident occurs in the wake of the night when no or very
workers are present, what will be the ranking in such a condition? Would the
ranking say that although a 15acre company burned down with no evacuations, it
cannot be ranked as severe?

loss of $100,000 by a company that has a working capital of substantially less
would have suffered a major loss and in their books, they may have suffered a
severe accident. A spillage into the Amazon of just about 100barrels of let’s
say crude oil will be considered less severe when the same spillage occurs in
one of the tributaries of the same river with a local village population of 150
depending on the water along that bank. Thus, volume spilled should be used in
conjunction with the affected population.

my opinion, this ranking or classification seems to want to limit the number of
accidents that usually fall under huge losses to the parties involved without
suffering the integrity of a global limit. This ranking, although commensurate
for those companies with a greater economic might, will not bode well for
economies whose GDP might not be as large as the estimates provided above.

I suggest that when this classification or ranking system is used, it should
state for a fact, the workforce population, the economic prowess of the company
involved, the economic standing of the nation under review and other factors
that can reflect on the extent of the loss for those parties involved.

Monday Michael's picture

Bhopal: 28 years after

On December 2nd 2012, it was the 28th anniversary of the Bhopal industrial disaster [1]. The disaster may not have been oil and gas related but still goes down as one of the worst industrial disasters. In my opinion, it is the worst industrial disaster the world has seen not just because of the number of victims (8,000 on the night of the disaster and about 25,000 afterwards) but by the way and manner the victims died- choked to death in their sleep by breathing Methyl Isocyanate (MIC) gas. Let us all spare a thought for the victims, their loved ones and all those affected either directly or remotely by this disaster. It is important for us as students of Safety and Risk Management to learn from this and other industrial disasters (much of which have been discussed on this forum already by other contributors), whether oil and gas related or not, so that in our respective places of work, we can imbibe practices that are safe and risk-free and ultimately prevent a recurrence of such industrial disasters.




Thomas Ighodalo's picture

"Everything we hear is an opinion not a fact"

I would like to further discuss on the definition of severity and critic one of the criteria as defined by The Paul Scherrer Institut(PSI) developed Energy Related Severe Accident database (ENSAD) in 1998, subsequently i would like to propose a modified version on the criteria required to tag an incident/accident as severe. According to ENSAD an accident is severe if it meets at least one of the following criteria

 1. There must be at least 5 deaths
 2. There must be at least 10 injuries
 3. The accident results in at least 200 evacuees
 4. There must be a large scale food consumpiton ban
 5. There is a release of hydrocarbons, over 10,000 Tonnes
 6. The company is placed under and enforced clear-up of the land or surrounding environment
 7. The company makes an economic loss of at least $5 Million (USD)

Firstly, my comment is on criteria 1 which states "There must be at least 5 deaths" The loss of a single human life can never be evaluated as such equating severity to the loss of 5 human lives is not acceptable (its akin to placing a value on a life)- i propose that The Paul Scherrer Institut(PSI) revise the criteria for severity to read Criteria 1. "There must be atleast 1 death" and the definitionn of Severity should also be revised to specify that an accident is severe if it meets either Criteria 1(revised "There must be at least 1 death) or Criteria 2 plus any other of the 5 remaining criteria (i.e items 3-7) previously stated.

Secondly, i find it an oversight to equate severity to the loss of at least $5million , this does not consider the effect of inflation over time- which will result in severity as defined by ENSAD to be constantly adjusted to account for inflation.

Mostafa Tantawi's picture

Mostafa Tantawi
Masters Of Subsea Engineering, University of Aberdeen

Piper Alpha 1988


Piper Alpha
was a large fixed Structure Platform located about 120 miles north east of
Aberdeen. The platform started production in 1976; its function was to collect oil and gas coming up the risers, and to separate those streams
into oil, condensate and gas. Piper Alpha was a hub or collection platform -
not only did it receive oil and gas from its own risers, two other platforms -
Claymore and Tartan 'A' - fed gas to it. Piper Alpha then exported the combined
gas streams to MCP-01. (It also used some of the gas for its own generators and
as lift gas.) Its oil was pumped to the Flotta Terminal.

Piper Alpha contributed about 10% of the oil production from the
U.K. sector of the North Sea.


At 10:00 pm 6th July
1988, a massive explosion and subsequent fire led to the destruction of the
platform. 167 men died on that day (including two crew men of rescue vessels),
As many of the persons of board was off duty and were located in the living
quarter, the smoke of the fire trapped these persons who accounted for most of
the fatalities. Only 61 men survived. The total insurance loss was estimated
about $3.4 Billion.

Initial Cause of Disaster:

Workers on the Piper Alpha
removed pressure safety valve (PSV) for maintenance. The technicians who
removed the valve fitted flange blinds to the pipe work but only tightened them
by hand. Condensate injection pump ‘A’ which supplied the pipe work had been
electrically isolated to prevent its use. The permit to work for the electrical
isolation was returned to the permit office, but the permit regarding the PSV
removal was not. Condensate injection pump ‘B’ was running in place of pump ‘A’
to inject condensate into the oil pipeline to be pumped to the mainland. During
the nightshift pump ‘B’ tripped out and failed to restart. Fearing that the
platform was nearing a total shutdown it was decided to restart pump ‘A’ to
continue injecting condensate. Referral to the permit system revealed that the
pump was electrically isolated, but as the PSV permit was not present it was
unclear that the pipe work containment had been broken. After removing the
electrical isolation, pump ‘A’ was restarted. This caused the release of large
amounts of condensate gas into module C. This was then ignited by an unknown
source which caused an explosion. The fire walls which separated the modules
were damaged by the explosion and this disabled the firewater supply and the
emergency power supply to the platform. Without the water deluge system
operational the fire spread rapidly causing a sequence of explosions.
Eventually the gas riser pipes which connect the Piper to the Claymore, Tartan,
and MCP-01 platforms failed individually, which caused a sequence of
catastrophic explosions. The staff on these platforms, although aware of the
explosion and fire on the Piper did not shutdown production immediately, and in
effect continued to fuel the fire. The platform continued to burn until it was
completely destroyed.

Actions after the Disaster:

After Piper Alpha Disaster
there was an initial response from the industry. Every offshore operator
carried out immediate wide ranging assessments of their installation and
management system, which included

to the permit to work management system

of some pipeline emergency shut-down systems

of Subsea pipeline Isolation systems (SSIV)

of Smoke Hazards

Evacuation and escape systems

of Formal Safety Assessment.

The industry invested around £
1 billion on these and other safety measurements, all this was before Lord
Cullen's public inquiry report.

Lord Cullen's Inquiry:

Lord Cullen official Public
Inquiry into the disaster comprised two parts. The first was to establish the
causes of the disaster. The second made recommendations for changes to the
safety regime. The inquiry began in November 1988; report was published in
November 1990.

Lord Cullen's Report:

Lord Cullen made 106
recommendations within his report, responsibility of implementing them were
spread across the regulator and the industry as following

57 for
Health and Safety Executive (HSE)

40 was
the responsibility of the Operator

8 for
the whole industry to progress in

1 for
the Stand-by ship Owners Association

All of the Lord Cullen
recommendations was accepted by the industry, so they acted urgently to carry
out their 48 recommendations and by 1993 all had been implemented.

Similarly the HSE developed and
implemented Lord Cullen recommendations which ended to the introduction of safety
regulations requiring the operator/owner of every fixed and mobile installation
operating in UK waters to submit to the HSE, for their acceptance, a safety



Technical Books, incidents, Piper Alpha"

"Wikipedia Article on
Piper Alpha"

"Piper Alpha Lessons Learnt PDF by Oil and Gas UK"

Kobina Gyan Budu's picture

Severity is defined as the degree of something undesirable, something hard to endure and excessive sternness 

In analysing the top ten severe energy accidents therefore, the criteria worthy of consideration include:

·           1. the release of a specified quantity of a dangerous substance

·           2. specified harm to persons (at least 1 death)

·           3. specified harm to the environment

 (, copied October 02, 2012)

·           4.  impact on economic concerns (costs)

·           5. post-traumatic disorder

Below gives a picture of the ranking.

 1.      1.   Banqiao Dam disaster in China (Date:08-Aug-75, fatality-26000 immediate, 145000 after due to famine and epidemic, 11 million people displaced)

2.       2.  San Juan LPG Tank Explosion, Mexico (Date: 19-Nov-84, fatality: 500 – 600, 5000-6000 suffered various degrees of burns)

3.       3.  Chernobyl, Ukrainian SSR ( Date: 26-Apr-86, fatality-56 immediate, 3944 after, 300000 people displaced, cost-$7B)

4.       4.  Piper Alpha disaster (Date: 06-Jul-88, fatality-167, 70% of survivors interviewed 10 years later reported psychological problems, cost-$3.4B)

5.       5.  Gulf of Mexico oil spill/Macondo Blowout (Date: 20-Apr-10, fatality-11, 17 injured, cost-$20B)

6.       6.  Texas City Refinery Explosion (Date: 23-Mar-05, fatality-15, 170 injured, Fined $21M. Another $87M failure to correct safety hazards revealed in 2005)

7.       7.  Norco Refinery Explosion, Louisiana (Date: 05-May-88, fatality-7, 42 injured, cost-$706M)

8.        8.  Kleen Energy Power station Explosion (Date: 07-Feb-10, fatality-6, 50 injured, cost-$16.6 fine)

9.        9.  Fukushima, Japan (Date: 11-Mar-11, fatality-1, 37 injured, fears/safety concerns with reactor # 4)

10.     10. The Exxon Valdez oil spill, Alaska (Date: 24-Mar-89, no fatality, crude spread over 11,000 square miles of ocean, cost-$287M for actual damages and $5B for punitive damages).



What were the physical/technical circumstances that led to the accident?

1.  Gaps in engineering designs – example is the Banqiao Dam which was not design to take the volume of water that poured in on the day of the accident (August 08, 1975). Also, designing 5 instead of 12 recommended sluice gates and not considering the number of dams on the one basin. The position of the cabin on the Piper Alpha rig also raises engineering concerns (left all the people who had authority to sanction further evacuation dead).

·                  2.  Technological Awareness – Lack of cutting edge technological awareness at the time of engineering designs. Communication technology was not efficient enough as can be seen in the Banqiao accident (communication between base station and the dam site was ineffective).

·                 3.   Natural Circumstances – Like heavy rainfall in the Banqiao accident and the Tsunami in Fukushima

·                 4.   Lack of Supervision – State institutions that were supposed to be overseers were not on top of issues

What were the main underlying causes?

1.  Safety breaches – Breaches in all the BP related accidents like (Gulf of Mexico oil spill/Macondo Blowout,  Texas City Refinery Explosion). In the Piper Alpha accident, a pump and its related safety valve were put under simultaneous maintenance without any proper safety measures in place.

·                   2.  No rigorous safety inspections done – example is the Norco explosion which was caused by a corroded pipe (proper routine process safety inspections would have picked that).

·                   3.  Lack of knowledge in Safety – In the Texas City refinery accident, the contractor would not have left his truck idling if he knew the consequence. The Kleen Power Plant explosion was believed to have been caused during a blow-down test. Blow-down is a part of everyday process so if conversant with it, there should not be a problem.  Another example is the government regulators that were found to be low in knowledge or authority to notice the cost-cutting decisions in the BP Deep Water Horizon accident by BP, Halliburton and Transocean.

·                  4.  No Proper Emergency Command Structure – The operators on the Piper Alpha connecting platform felt there was no order to stop production so even though Piper Alpha had had an explosion, they should continue pumping crude, how ridiculous.

Why did the accident result in: (i) So many fatalities; (ii) So much harm to the environment etc.?

1.   Many of the accidents happened in peak periods when people were at work.

·                   2.  People were taken unawares as they had not been prepared by regular exercises (i.e. safety talks, routine emergency drills, safety audits etc).

What factors contributed to the escalation of the accident?

1.  Un-readiness of systems to manage major undesired consequences/accidents

·                   2.  As a result, in-appropriate emergency management plans in place

What were the legal consequences of the accident?

1.   Corporate man-slaughter

2.   Revocation of operating company licenses and individual personnel certifications

·                   3.  Huge compensations to victim’s families

·                   4.  Reputational damage

·                   5.  Imprisonment etc




Mark Nicol's picture

I would put the Aberfan mining disaster in Wales
as number  on your list due to the number
of fatalities (116).

The spoil tips produced by the mining process were placed on top
of a layer of porous sandstone that housed a number of underground springs. On
the lead up to the disaster it had been raining heavily for days which caused approximately
3-6 meters of the spoil tip to subside.

The root cause of the disaster was that the spoil
tip became saturated with the heavy rain fall which caused the spoil tip to
subside at the top which resulted in 150,000 cubic meters of mining waste to
flow down the hill. Secondly there was the lack of procedures that were in
place for the tipping of the spoil tips. The NCB (national coal board) had
tipping policy and also did not follow any regulatory body i.e. Her Majesties
Inspectorate of Mines and Quarries.   

The village had no defence systems in place for
such an occurrence. As such, the spoil tip mass aided by gravity, destroyed the
houses and parts of the school with relative ease. As the disaster happened in
the morning when the children had just arrived for class the fatality rate was
greatly increased.

The lack of procedures in place for dumping the
spoil contributed to the escalation of the accident.  If procedures had been in place for the likes
of safety, risk analysis and geotechnical surveys to determine the condition of
the spoil tip, this would have significantly reduced the accident happening.   

As a result of the accident the Mines and
Quarries (Tip) Act 1969 was introduced to address the spoil tips produced by
mining. This Act was an addition to the Mines and Quarries Act 1954 which had
no reference to spoil tips






FELIXMAIYO's picture

In the ranking of the top 10 energy related accidents I have decided to look at it in a different approach by ranking them on the various energy forms .I have considered the oil and gas industry. Decided to approach it in two ways: offshore and onshore.


Year                                        Field /operation            No. of fatalities                     No. of injuries

1988                                       Piper Alpha                           167                                          60

1980                                       Alexander L Kielland              123                                          N/A

1989                                       Seacrest                                91                                            0

1982                                       Ocean Ranger                         84                                            0

1983                                       Glomar Java Sea                     81                                            0

1979                                       Bohai II                                  72                                            0

1986                                       Brent field                               45                                            2

1984                                       Enchova Central                      42                                            19

2003                                       Neelam field                            27                                             0

1995                                       DLB 269                                  26                                             0


1984                                     Bhopal, Madhya Pradesh                          >2000                    >170000

1994                                     Dronka                                                   >580                            -

1984                                     San Juan Ixhuatepec, Mexico city              >500                         2500

2003                                     Gao Qiao, Chongqing                                  243                         4000-9000                           

1982                                     Tacao                                                      >153                         500

1997                                     Visakhapatnam, Andhra Pradesh                >56                           20

1970                                     Semarang, Java                                         50                              

1998                                     Xingping, Shaanxi                                       50                            100

1979                                     Bantry Bay, Cork                                        50                               -

1992                                     Dakar                                                        41                             403




Trevor Strawbridge's picture

As I am unsure this has been uploaded succesfully Please forgive the second submission (Still getting used to this site)

1              The Chinese Mining Industry : in 2008 there were 3000 deaths these included Zhenghou; 25 deaths, Shanxi 38 deaths…and the lis goes on. The underlying issue here appears to be lack of regulations and hence less regard for workers well being before profit. Many of the accidents are attributable to poisonous or volatile gases. Chinese government has blamed illegal production and although safety improvements and procedures are being introduced they are still very often ignored. Until Government can enforce these, the situation is unlikely to improve. The PRC government see the enforcement costly, and difficult due to geographical problems associated with enforcement. For example many of the mines are located in rural areas that are remote and difficult to access. It appears that this growing economy still has a long way to go achieve safety standards that we in Europe are accustomed to. 

2              St Frances dam break 1928 resulting in 450 deaths, and the destruction of the town of Santa Paula. The cause was found to be a result of an ancient geological landslide on the eastern side of the dam. The 1920’s technology was not advanced enough to identify this. The damn collapsed as a result of the full hydrostatic load in the reservoir after a heavy rainfall. Thus exerting excess stress to the eastern side. To put this into perspective; the construction’s foundations were unsuitable on the eastern side of the dam and collapse was certain. The release of the Flood wave said to be in excess of 40m cascaded the town of Santa Paula. During the inquiry there was conflict between the Government departments, the geologists and the design and engineering departments. The hearings in the aftermath  recommended that "the construction and operation of a great dam should never be left to the sole judgment of one man,  

3              Piper Alpha 187 deaths. Lead to radical change in regulations for offshore installations. The incident was said to have been caused by miscommunication during a maintenance operation on a Pressure relief valve. This was said to have been moved from a gas compression module and replaced by a blind flange. The flange was only hand tightened as the operations were said not to restart until later in the day. When they did restart the Valve was missing and the flange was still only hand tight. Ignition was then imminent.  Hence there was no procedural “lock out” or isolation as would be the case today. The Cullen report was issued in the aftermath and a series of recommendations were implemented; including the necessity for Duty Holders to produce a safety case. The introduction of several Statutory instruments were also introduced which regulated the design and construction of offshore installations. Initially this was regulated by the Dept of Energy but nowadays it is policed by the Health & Safety Executive. The report was also critical of Piper Alpha's operator, Occidental, who were found guilty of having inadequate maintenance and safety procedures. But no criminal charges were ever brought against them. Had these safety procedures been implemented and practiced there would have been a strong possibility that more workers could have escaped, but more importantly; the incident may never had occurred.

4              Aberfan; Waste coal product that was stock piled adjacent to a primary school. After a spell of poor whether the waste and deluge had cascaded; as would a normal landslide, and buried the primary school. 116 children and 28 adults were killed. Today we are aware that such a pile would be hazardous but back in 1966 this was not the case. The government appointed Mines Inspectorate were only employed to ensure that the mines themselves were safe. Lord Robens the Chairman of the NCB had been seen to be callas by the public and did not visit the site until his return from holiday. Indeed when ordered to make the site safe he used £150000 from the public donations fund to remove the waste to safe disposal. The following Davies Inquiry had found the NCB responsible for this disaster and the Government had introduced Her Majesty’s inspectorate of mines and quarry’s, along with new legislation. During Tony Blairs reign as Prime Minister the £150,000 was returned to the fund with an apology but no interest was paid. The disaster itself happened very quickly without any prior warning. The timing unfortunately played a key role as the children in the school were all assembled in the main school hall, which was directly in the “line of sight” of the land slide. That day the visibility was said to be 50m but clear at the top of the heap. The previous wet weather had played a big part in releasing the product.  

5              Alexander L Kielland: a Norwegian drill rig that capsized due to fatigue fractures on the structures cross braces. 123 deaths. In 1980 the platform had just completed a campaign at EDDA and was anchored offshore when the weather had seen 40 knot winds with 12m waves. Whist the majority of the 200 workers on board were off duty in the cinema, a loud crack was observed and it transpired that 5 out of 6 of the anchor chains had broke and the platform started to capsize. The list increased during which time the workers had tried to evacuate but experienced major difficulties releasing the life crafts. In fact of the 50 life crafts on board only one was successfully launched. Whilst the evacuation was in progress the final anchor had gave way, and the structure capsized. Investigations found that a small fillet weld to attach a hydrophone bracket to a cross brace was incompletely welded and thus caused a stress point in the cross brace. This had failed causing the bracing to collapse in the attributed storm. It was later found that the design of the platform had not allowed for any redundancy in its structure. Furthermore the evacuation procedures were criticised and the lessons learned from this had been implemented in the OPITO type safety training we know today. Finally the one contribution that may well had been the route cause of the accident, is that the platform was originally built as an accommodation module only and had makeshift modifications applied to it for oil exploration.

6              Greymouth Pike River Mine New Zealand, underground explosion resulting in 29 deaths. A total of 4 explosions were detected. The cause of the explosions are still unclear but were there is definitive evidence of an abundance of Methane Gas present. The possible safety measures not used in the Pike River Mine were; a "tube bundling" gas measurement system, stocks of food and water, breathing apparatus, and a second entrance. These are mandatory requirements in UK mining but it is still unclear whether this was a key factor in the loss of these lives. The Investigation is still ongoing   

7              Deep Water Horizon / Macondo  Gas blow out. Appears to be failure of safety equipment to function in an emergency resulting in 11 deaths and a catastrophic environmental disaster. Investigation is still ongoing. Latest reports suggest that procedures were not followed and Safety equipment such as blow out preventers were not fully tested before use. The Whitehouse oil spill commission leading the inquiry has collectively blamed Halliburton, Transocean and BP for making time and money savings whist compromising the integrity of the well. Some of the failures in procedures included failure to run cement bond tests , the use of a cement diagnostic tool, ignoring failed pressure tests etc. The committee did not, however, place the blame on any one of these events. More so it concluded with the following statement blaming the management of Macondo “Better management of decision-making processes within BP and other companies, better communication within and between BP and its contractors and effective training of key engineering and rig personnel would have prevented the Macondo incident” The jury is still out with this incident and I can only assume that more evidence will be revealed as the litigation process continues 

8              Fukushima Nuclear power station. Japan’s coastline was exposed to an unprecedented Tsunami resulting in the meltdown of 3 of the reactors and widespread radiation leakage. There were 37 injuries at the time of the incident although it is too early to establish the full extent of long term effects. Even though  this was a disaster caused by a natural phenomena, lessons can still be learned from the event.   

9              Chernobyl ; Ukraine former eastern block nuclear explosion in reactor 4 resulting in an initial 31 deaths and a radioactive leak that has lead to illnesses and fatalities including thyroid cancer. There was a sudden power output surge, and when an emergency shutdown was attempted, a more extreme spike in power output occurred, which led to a reactor vessel rupture and a series of explosions. The INSAG (The International Nuclear Safety Advisory Group) had concluded that there were gross violations of regulations but the USSR state committee had disagreed and reassessed the causes. They state that the INSAG’s assessment was too erroneous and stated that items such as the turning off of emergency systems is not a violation. Following the accident, questions arose about the future of the plant and its eventual fate. All work on the unfinished reactors 5 and 6 was halted three years later. However, the trouble at the Chernobyl plant did not end with the disaster in reactor 4. This reactor was sealed off in concrete whist the other reactors were still in service due to the energy shortage created by the disaster. 

10           Iraq gulf war. Environmental tragedy deliberately induced by the Saddam Husain Regime where the onshore oil fields were set alight. The disaster is man made as a result of a political war that today is seen by many as illegal. Husain had ordered the wells to be set alight  to ensure the oil was not taken by his enemies                                                                                                                               

Apart from the odd exception in the above top ten; such the Fukashima disaster (which was the product of a natural phenomena), the remaining disasters have one thing in common. They were all avoidable. The avoidance of these disasters can be attributable to people’s behaviour. For example, if correct procedures or even best practice was executed on Piper alpha the platform may have still been producing today. If the Chinese mining regulations’ were followed maybe many of the fatalities would have been averted. Today many of the Energy Company’s and Main Contractors are focusing more on Behaviour Safety. The thought behind this is to encourage employees to alter their unsafe habits regardless of how great or small the consequences may be. This may be as simple as holding the hand rail whilst ascending or descending a stairwell. The concept here is that; whilst tools are available such as procedures, risk assessments, correct equipment etc, there is a need to focus on correct use; ie follow procedures, use equipment as instructed by manuals etc. To put this concept in perspective consider a situation where you have just put your new shoes on for a night out. Your lace is undone and unnoticed. You are then descending a stairwell and you trip. Case 1: you are not holding the hand rail, and the likely consequences from an inevitable fall could be anything from a minor injury, serious injury that may have lifetime affects or even death. Case 2 you are holding the hand rail and you trip. The natural body reaction would be to tighten the grip on the hand rail reducing the likelihood of a fall. Indeed the likelihood is that you would probably end up in a sitting position on the stair with a few bruises or a sprained wrist from the grip. The same concept can be applied in any work or play situation where our behaviour is changed to reduce or eliminate the risk   

Trevor Strawbridge Student Number  51233708 

Harrison Oluwaseyi's picture

Before listing some
of the most tragic incidents in the energy sector i believe there should be an
understanding of what the word severe accident means. An accident is simply
described as any unplanned event or acts those results in damage to property,
material, equipment or personnel injury or death. The word "severe
accident" basically has no definition tagged to it but "the PSI
database ENSAD uses seven criteria to define it:

1) at least five fatalities or

2) at least ten injured or

3) at least 200 evacuees or

4) extensive ban on consumption of food or

5) releases of hydrocarbons exceeding 10 000 t or

6) enforced clean-up of land and water over an area of at
least 25 Sq km

7) economic loss of at least five million USD(2000).

whenever any of this criteria is satisfied, the accident is
termed a "Severe accident"".

Below is the list:

1) 1975-China"Banqlao/shimantan dam break 26,000dead

There have been several speculations about the cause of this
disaster. Officials have blamed this Incident on the failure of the dam due to
poor engineering works. It was said that a "once-in-2000-years"flood occurred.
When this happened communication to and from the dam was lost and the released
waters caused a wave and also creating lakes.

2) 1984, Brasil, explosion and fire at oil pipeline, 500

3)1986-Ukraine, Chernobyl reactor accident 31 immediate
fatalities, up to 33,000 estimated

Latent fatalities, 135,000people resettled ($200billion)

Different parties have blamed this incident on different
groups but the IAEA have put out

Two major reasons why this incident happen: the operator had
little or no knowledge

of nuclear and atomic physics and engineering, had no
training and experience.

The other, been no avenue was created for an emergency
system in case of a mishap.

 4) 1988-UK, Piper Alpha disaster, 167 dead, cost of about
$3.4 billion


 5) 1979- Canada, Series of explosion after derailing of
several tank cars filled with liquid petroleum gas(LPG), 250,000persons in
affected area evacuated


6)1979- Gulf of Mexico, well blowout on oil platform "lxtoc
1"loss of 480,000 t crude oil between June 1979 and Feb. 1980

7) 1979-USA, reactor accident at "Three Mile
Island" plant, no death, 200,000persons

Temporarily evacuated

8)1976- USA, failure of 'Teton' dam 14 dead, 2.7billion USD
total damages

9)2002-Spain, The Prestige Oil tanker carrying 77,000tons of
heavy fuel


10) 1989-USA Tanker "Exxon Vaaldez "loses 37000 t
crude oil, 2.5billion USD clean-up costs, 9.5 billion USD total cost.

Elle Allswell David's picture

Disasters and accidents occur as a consequence of the impact of a natural or man-made hazard. By severe accidents we understand potential or actual accidents that represent a significant risk to people, property and the environment and may lead to large consequences. 

Energy related Severe Accidents Database (ENSAD) uses seven criteria to define a
severe accident in the Coal, Oil, Gas, Hydro or Nuclear Chain:  

1.    At least 5 fatalities or 

2.    At least 10 injured or  

3.    At least 200 evacuees or  

4.    Extensive ban on consumption of food or  

5.    Releases of hydrocarbons exceeding 10000t or   

6.    Enforced clean-up of land and water over an area of at least 25km2.  

7.    Economic loss of at least 5 million 2000 USD.  

Whenever anyone of the above criteria is satisfied then the accident is considered as Severe. For the course of this study I will be using case1 number of fatalities.

 number of immediate deaths

Banqiao Dam, China 
 Typhoon Nina

 Machhu II, India
Dam failure 

Benxihu Colliery, China 
Coal Dust explosion

Hirakud, India 
Dam failure 

Asha-Ufa, Sibera 
liquefied Petroleum gas 

 Durunka, Egypt
fire in oil tank 

 Cubatao, Brazil
oil fire 

 Warri, Nigeria
Fire in oil Pipeline 

Liquefied petroleum gas 

Dobrinja, Yugoslavia 
Coal mine's picture


As we known, Banqiao Dam disaster is the top 1 sever accident in the world, about 29 towns and 12 million populations suffered this terrible accident. In addition, the most famous train line from Beijing to Guangzhou was blocked by 18 days and it started to work again after 48 days. Consequently, the total loss is about 10 billion.

There are three reasons for this horrible disaster. The first one is the typhoon which makes a huge contribution to the rain. The max rain drop for one day is 1005 millimetre and it is far more than the average records among this area. The second is the design of the dam which has a lot of problems.  In other way, it means not only the structure engineers, but also the geologists did not design strictly and several parts of the dam were broken such as the gates. The third reason is that this incident happened before dawn and most people were sleeping at that time. This situation is the same as Tangshan earthquake in 1976.

In my view, I think the reason for less people realize this catastrophe is that Chinese government controlled the Media and blockaded the information. Perhaps, they wanted to conceal the truth of this damage or they wanted to keep social stability for the fear will probably influence the development of the community.  Nevertheless, I think we have the right to know or learn from this failure so that we can prevent the next same failure. On the other hand, usually, after the accidents happen, all of the people want to find someone to blame and to responsible for this affair, but I think we should realize the reasons for failure and warn the later generation to get rid of it rather than punishment.



Xingyuan fu's picture


I want to talk about the media which help us to realize the disasters worldwide.We can not deny that all of us come to realize the failure through the media. Normally, we receive the different kinds of information about the accidents from newspaper, TV programs and the internet all over the world, but unfortunately, some of their reports may not true about the accidents. Thus, what shall we do? Shall we choose to believe what we hear from the media?  If they say government should be responsible for this accident, most of us will trust them and start to blame the government. Nonetheless, what if the real reason is the ill management from the company? There is a phrase ‘public opinion’ and media has the power to lead the public opinion no matter that view is right or wrong. Moreover, there is also a statement that ’all the numbers in media is not correct’. Actually, this comment is too absolute, but I think it is not out of the thin air. Finally, for us engineers, in my opinion, if we can, we should analyse the accident by ourselves and make a conclusion. To believe what the media say about the disaster is not the good way to find the hidden truth.  Regards

Xingyuan fu

Duo Wu's picture

10. Thule air base B-52 crash
WHERE: Thule Air Bash, Greenland
WHEN: January 21st, 1968
DETAIL: The aircraft was carrying four hydrogen bombs on a Cold War "Chrome Dome" alert mission over Baffin Bay when a cabin fire forced the crew to abandon the aircraft before they could carry out an emergency landing at Thule Air Base. The bomber crashed onto sea ice in North Star Bay, Greenland, causing the nuclear payload to rupture and disperse, which resulted in widespread radioactive contamination. The United States and Denmark launched an intensive clean-up and recovery operation, but the secondary of one of the nuclear weapons could not be accounted for after the operation completed.

9. Tokaimura nuclear accident
WHERE: Tokaimura, Japan
WHEN: September 30th, 1999
DETAIL: The criticality accident occurred in a uranium reprocessing facility operated by JCO (formerly Japan Nuclear Fuel Conversion Co.). The accident occurred as three workers were preparing a small batch of fuel for the Jōyō experimental fast breeder reactor, using uranium enriched to 18.8% with the fissile radionuclide known as U235. It was JCO's first batch of fuel for that reactor in three years, and no proper qualification and training requirements appear to have been established to prepare those workers for the job.

8. Windscale fire
WHERE: Windscale, United Kingdom
WHEN: October 10th, 1957
DETAIL: It was the worst nuclear accident in Great Britain's history, ranked in severity at level 5 on the 7-point International Nuclear Event Scale. The two piles had been hurriedly built as part of the British atomic bomb project. Windscale Pile No. 1 was operational in October 1950 followed by Pile No. 2 in June 1951. The accident occurred when the core of the Unit 1 nuclear reactor at Windscale, Cumberland caught fire, releasing substantial amounts of radioactive contamination into the surrounding area. No one was evacuated from the surrounding area, but there was concern that milk might be dangerously contaminated. A 2010 study of workers directly involved in the cleanup found no significant long term health effects from their involvement.

7. Kyshtym disaster
WHERE: Mayak, Russia(was a part of the Soviet Union)
WHEN: September 29th, 1957
DETAIL: It measured as a Level 6 disaster on the International Nuclear Event Scale, making it the third most serious nuclear accident ever recorded. The event occurred in the town of Ozyorsk, a closed city built around the Mayak plant. Since Ozyorsk/Mayak was not marked on maps, the disaster was named after Kyshtym, the nearest known town.

6. Three Mile Island accident
WHERE: Dauphin County, Pennsylvania, United States
WHEN: March 29th, 1979
DETAIL: It was the worst accident in U.S. commercial nuclear power plant history, and resulted in the release of small amounts of radioactive gases and radioactive iodine into the environment. The nuclear power industry claims that there were no deaths, injuries or adverse health effects from the accident, and a report by Columbia University epidemiologist Maureen Hatch agrees with this finding.

Duo Wu's picture

5.       The Bohunice Nuclear Power PlantWHEN: Feb 22nd, 1977WHERE: Jaslovske, Westen SlovakiaDETAIL: The A-1 reactor which is designed by Soviet Union suffered a major accident during refueling, rated INES-4. A report said this reactor is ingenious but not  mature in technology, the seeds of disaster been planted at the very start. This reactor is currently undergoing a decommissioning and cleanup process. 4.       The SL-1 steam explosionWHEN: Jan 3rd, 1961WHERE: Falls, Idaho, United StatesDETAIL: Stationary Low-Power Reactor Number One (SL-1) was a United States Army experimental nuclear power reactor which underwent a steam explosion and meltdown, killing its three operators. The direct cause was the improper withdrawal of the central control rod, responsible for absorbing neutrons in the reactor core. The event is the only known fatal reactor accident in the United States. 3.       Yucca Flat Baneberry TestWHEN: Dec 18th, 1970WHERE: Yucca Flat, United StatesDETAIL: Yucca Flat has been called "the most irradiated, nuclear-blasted spot on the face of the earth". The Baneberry 10 kiloton test detonated 900 ft below the surface but its energy cracked the soil in unexpected ways, causing a fissure near ground zero and the failure of the shaft and cap. A plume of fire and dust was released three and a half minutes after ignition, raining fallout on workers and six workers were affected by the radiation. 2.       Fukushima Daiichi Nuclear DisasterWHEN: Mar 11th, 2011WHERE: Futaba District of Fukushima Prefecture, Japan 1.       Chernobyl DisasterWHEN: Apr 26th, 1986

WHERE: Chernobyl Nuclear Power Plant, Ukraine

Duo Wu


Abdulazeez Bello's picture

In ranking the top ten severe accidents in the energy
industry, the Number of fatalities recorded was the basis of judgement. The
Chernobyl nuclear disaster ranked first due to the potency of its danger in
present day after 25 years though it did not record the highest fatality rate.


Ukraine April26, 1986. The total number of death recorded is still being
disputed. The area has remained unsuitable for human habitat cutting across
three countries: Russia, Ukraine and Belarus.

  Two large dams (Banqiao Dam and Shimandan
) recorded a death toll of over 26,000 In  Zhumadian, China August 4-8, 1975

Machchu II:
A dam failure with death toll in the region of 25,000 happened in Morvi, India
August 11, 1979. The cause of accident was attributed to poor Engineering

methylisocyanate gas leaked from a pesticide plant into a densely populated
area of Bhopal, in central India killing more than 10,000 people.

Vaiont Dam:
An arch dam whose left bank was actually the toe of an ancient landslide. The
ancient slide became unstable in October 1963 displacing water which generated
a gigantic wave causing more than 2,000 deaths.

: Coal dust explosion at the Honkeiko coal mine near Benxi in
Japanese-occupied Manchuria, 1,549 miners died, 26 April 1942

 Courrieres Mine disaster:  1,099 miners (this included many young
children) died in a coal dust explosion in Courrieres, France, 10 March 1906,

A gas explosion at the Mitsubishi Hojyo coal mine in Kyushu, Japan, killed 687 miners,
making it the deadliest mine accident in Japan's history. Decembber, 15, 1914,

An explosion at the Laobaidong mine in Datong, Shanxi province killed 684 miners,9 May

San Juanico
: large quantities of LPG leaked from a pipeline. The (heavy)
LPG-gas dispersed over the wall into the surroundings and was ignited by fire
resulting in over 550 deaths.

1.Consequences and countermeasures in a nuclear power accident: Chernobyl
Biosecurity and bioterrorism [1538-7135] Kirichenko, V A yr: 2012 vol: 10 iss:
3 pg: 314 -320 

2. Lessons from catastrophic dam failures in August 1975 in
Zhumadian, China
GeoCongress 2008: Geosustainability and Geohazard Mitigation (GSP 178)
[0-7844-0971-4; 0-7844-7226-2] Xu, Y, yr: 2008 pg: 162 -169 

3. The Inundation of Morvi
Economic and Political Weekly Vol. 14, No. 34 (Aug. 25, 1979), p. 1454

4. The Bhopal tragedy: 25 (10 +15) years after | La tragedia
di bhopal: 25 (10+15) anni dopo
 Assistenza infermieristica e ricerca
[1592-5986] Tognoni, G yr: 2010 vol: 29 iss: 2 pg: 94 -103

5. Catastrophic Slide: Vaiont Landslide, Italy
Geomechanics of Failures. Eduardo E., Núria M., Alexander M., Advanced Topics
2010, pp 33-81


 Journal of Hazardous Material, 20.  C.M. PIETERSEN   (1998) 85-107
ElsevierSciencePublishersB.V., Amsterdam


Ahmed_Abdelkhalek's picture

In terms of
financial losses, the top 5 severe accidents (considering 2012 prices) are;

1.       Fukushima
nuclear accidents, Japan

       Financial Losses: > ¥ 2 trillion ($
250 billion) [1]

2.       Deep-water Horizon oil spill, USA,2010

      Financial Losses: > 50 $ billion [2]

3.       Chernobyl disaster, Ukraine, 1986

      Financial Losses:

       2012 prices (considering inflation), $ 31.53 billion

     Based on $ 15 billion [3]

4.       Exxon Valdez oil spill,USA,1989

       Financial Losses:

       2012 prices (considering inflation), $ 11.89 billion 

       Based on $ 6.4 billion [3]

5.       Piper Alpha, UK,

       Financial Losses:

       2012 prices (considering inflation), $ 6.62 billion 

       Based on £ 1.7 billion ($ 3.4 billion) [4]


Values of the financial losses for relatively old accidents were
modified to consider the inflation to the current to enable comparison. Today
costs were calculated using Coins.Net “Inflation calculator” (

[1] ‘UPDATE 1-Tepco has almost $10 billion loss after Fukushima’,
Reuters, 14 May 2012. Available at:
[Accessed 14 October 2012].

[2] Paula Dittrick, “BP agrees to pay $7.8 billion in Macondo
settlements”, Oil & Gas Journal, 19 April 2012. Available at:
[Accessed 14 October 2012].

[3] ‘List of Disasters by Cost’, Wikipedia, Available at:
 [Accessed 14 October 2012].

[5] ‘Piper
Alpha’, Wikipedia, Available at:
[Accessed 14 October 2012].

Henry Tan's picture

It is not easy to collect financial data. How about the other 5 accidents in the top 10 ranking?

Ahmed_Abdelkhalek's picture

Indeed Dr. Tan that is why I suggested a group work on that regards. As for the rest 5, I will work on it but I hope that the effort exerted in the top 5 earned me a mark.

Ahmed_Abdelkhalek's picture

Accidents with Ranks 6 to 10

6.Prestige oil spill, Spain, 2002

2012 prices (considering inflation), > $ 3.2 billion  

Based on € 2.5 billion [6] 

7.Texas City Refinery explosion, US, 2005

2012 prices (considering inflation), $1.9 billion  

Based on $1.6 billion [7] 

8.Hertfordshire Oil Storage Terminal fire, UK, 2005

2012 prices (considering inflation), $1.380 billion  

Based on £ 700 million ($1.317 billion) [8] 

9.Shell Oil refinery explosion, US, 1988

2012 prices (considering inflation), $1.380 billion  

Based on $706 million [9] 

10.Bhopal disaster, India, 1984

2012 prices (considering inflation), $876.77 million  

Based on $470 million @1989 [10] 


Values of the financial losses for relatively old accidents were

modified to consider the inflation to the current to enable comparison. Today

costs were calculated using Coins.Net “Inflation calculator” (

[6] ‘Prestige Oil Spill’, Wikipedia, Available at [Accessed 14 October 2012].

[7] ‘Texas City Refinery explosion’, Wikipedia, Available at  [Accessed 10 December 2012].

[8] ‘List of industrial disasters’, Wikipedia, Available at [Accessed 10 December 2012].

[9] ‘List of industrial disasters’, Wikipedia, Available at [Accessed 10 December 2012].

[10] ‘Bhopal disaster’, Wikipedia, Available at [Accessed 10 December 2012].

Dike Nwabueze Chinedu.'s picture

In my opinion the most disastrous (that is number one accident) in history is the Banqiao reservior dam. It is a dam on the River Ru in Zhumadian prefective, Henan province, china [1].

The catastrophy happened in 1975 during typhoon Nina and about 171,000 people were killed in the incident [1].

The main underlining cause of the accident was that more than a year rainfall fell in 24hours which weather forecasts failed to predict. Thus, when the flood
water level rose, the sluice gates were not able to handle the overflow of water, partially due to sedimentation blockage, and again the wave protection
wall failed [1].

The rate at which the water travelled contributed to the escalation of the accident and thus the high number of fatalities recorded.

In the bid to save itself, the government attributed the disaster as natural as opposed to man-made even when it was clear and pointed out that a crack
appeared after completion of the construction of the structure.

No severe legal consequences were recorded.

Available: online [accessed: October 16, 2012]

Dike Nwabueze Chinedu.'s picture

In my opinion, the second most disastrous accident in history is the Bhopal chemical plant disaster. It happened in India at the union carbide pesticide plant between 2nd - 3rd december 1984 and over 4000 people were killed [1].

The immediate cause was the uncontrollable release of toxic gases into the atmosphere and the underlining cause was bad maintenance practice and lack of attention to safety rules. The runaway reaction which was started when water entered the tank was accelerated by the presence of contaminants, high teperature and corroded pipes.

In this accident we also see the compromise of safety at the expense of production as the safety system was switched off to save money and to allow larger storage of the chemical than safety system could allow.

Within few days of the disaster, trees in the vicinity became barren and over 2000 bloated animal carcasses had to be disposed. The factory was later closed in 1986, area around the plant was used to dump hazardous waste, thus making it toxic - these are all signs to show that the aftermat effect was also high.

The officials of the company blamed the accident on ‘employee sabotage' and not faulty design or operation, - this is usually common statement in most industrial accidents.


Neil Fraser James Carr's picture


No.       Accident           Year     Fatalaties

1          Banqiao
Dam disaster, China     1975     26,000-171000[3]

2          Chernobyl,
Ukrainian SSR          1986     Approx 4000[2]

3          Bhopall,
India    1986     Approx 4000[2]

4          San
Juan, Mexico          1984     500– 600[2]

5          Piper
Alpha disaster      1988     167[1]

6          Alexander
Kielland         1980     123[1]

7          Aberfan,
UK      1966     116[2]

8          Seacrest
          1989     91[1]

9          Ocean
Ranger   1982     84[1]

10         Glomar
Java      1983    81[1]

(I have only included recent accidents and limited
my search to 1950 onwards as reporting and analysis prior to this seems a
little ambiguous and my list is not exhaustive however i could not find further
information on some of the other disasters that i found mainly mining disasters
in china)

I have ranked these by casualties from
the events, the under lying theme I have taken from these events are that on a
positive note all of the major accidents have brought attention to shortfalls
in the industry’s they are involved in. with this it can be assumed that
accidents of the nature of above are a thing of the past with the real risk
being in emerging industry’s where the risks are currently not founded on good
historical information.

I have only included recent accidents and limited
my search to 1950 onwards




Andy Reid's picture

An explosion on the BP Deepwater Horizon drilling platform killed 11 crew members, injuring a further 17. It then went on to produce the largest oil spill of its kind in US history[1] spilling nearly 5 million barrels of oil into the ocean[2]. The probability of a spill from this site was deemed to be significantly small to merit an environmental impact study being overlooked[3]. An explosion was caused by a methane gas leak up the drill column, through several seals and barriers[4]. The gas leak is believed to be caused by inadequate cementing of the production casing[5] which is allegedly a result of cost-cutting measures from BP[6]. The incident is estimated to have cost BP $40bn[7]. When you compare this figure to the estimated value of a human life, typically $5m-$10m[8] then although the Horizon incident "only" cost 11 workers their lives, its financial damage to BP is equivalent to the loss of 4,000. The release of oil couldn't be stopped using ROV intervention[9] and several attempts were made to cap the well before oil flow could eventually be stopped nearly 3 months later[10]. BP has been accused of gross negligence in the run up to the incident with trial scheduled for January 2013. A finding against BP here could quadruple the civil damages BP owe and add approx. $15bn to their total costs[11]. Although the fatality count in this accident is comparatively low, it was an avoidable[12] event which resulted in massive environmental[13] and economic[14] [15] damages.

Consequently: the BP Horizon incident, although having a lower casualty count than other Energy Sector disasters, is one of the worst to have ever occurred.


Andy Reid
















Andy Reid's picture

The Ocean Ranger was a semi-sub offshore platform which sank off the coast of Canada when it was hit by a large wave, killing all 84 crew members. When the wave hit it broke a port light which allowed water ingress into the ballast control room. This, in turn, caused the ballast control panel to malfunction, triggering a forward list. The forward list caused flooding, exacerbating the list eventually leading to capsize. No personnel on board were trained to override the ballast control panel, nor were there any detailed instructions available[1]. The legal damages for those responsible settled out of court for an estimated $20m[2].

This disaster was incredibly unfortunate and could have been avoided by either having the rig manned with all appropriate personnel or even something as simple as a user manual for the ballast control system being on board.


Andy Reid



Andy Reid's picture

The offshore "floatel" Alexander Kielland was being utilised as accommodation for 200 offshore workers when a complete structural failure of all six of its anchor cables resulted in capsize[1] killing 123 men. It is claimed by some that the failures were a result of deliberate sabotage and there are calls from a group called FALK International to place pressure on the government to launch a formal investigation into the root cause of the failure[2]. Officials at the time of the incident claimed that the rig's leg had failed due to overloading while filling it with ballast[3].


Andy Reid




Andy Reid's picture

The Piper Alpha production platform exploded killing 167 of the 226[1] men on board. The specific root cause of the incident is under contention[2] due to the nature of the explosion and the number of eyewitnesses who lost their lives. It is, however, commonly accepted that the underlying cause of the disaster was a gas leak brought about by a safety valve being removed for maintenance but this information not being carried forward from the dayshift to nightshift crews. The Piper Alpha disaster escalated so radically due to several unfortunate circumstances. The initial explosion in the control room killed most of the personnel in a position to order an emergency evacuation. Furthermore, the nearby Tartan and Claymore rigs continued to pump oil and gas into Piper Alpha because nobody on board felt they had authority to halt production, even though they could see Piper Alpha burning[3].


The Piper Alpha incident was a tragic culmination of there being just a few missing links in paperwork, procedure and documentation with devastating results. In the aftermath a massive overhaul of safety procedures took place to try to ensure nothing on that scale happened again[4].


Andy Reid





Andy Reid's picture

A series of explosions at an LPG tank farm in San Juanico, Mexico led to the death of between 500 and 600 people, as well as 5000 to 7000 suffering severe burns[1]. It is believed that a pipe leakage or rupture due to excess pressure is responsible for the buildup of a large vapor cloud over the area which ignited causing a series of explosions[2]. A lack of gas detection systems is blamed for the extreme escalation of the flames and explosions[3].


San Juanico was another completely preventable tragedy. A gas/leak detection system could have shut down gas flow before the vapour cloud built up the volume it did.


Andy Reid




Andy Reid's picture

A large dust cloud explosion down a coal mine in Courrières, France resulted in the death of 1,099 people plus many more suffering severe burns. The source of ignition cannot be confirmed with certainty but it is believed to be attributable to either methane fumes being ignited by the naked flame on a miner’s lamp or mishandling of mining explosives[1]. A rescue party of 40 men are included among the lives lost as their entrance shaft collapsed upon them as they were entering the mine to begin rescue attempts[2]. The Courrières disaster is the worst mining accident to ever happen in Europe.


Andy Reid



Andy Reid's picture

A coal dust explosion killed 1,549 mining workers in China in the worst disaster in the history of coal mining[1]. The mine was located in an area of Chine which was under Japanese occupation. The Japanese authorities attempted to quell the flames by closing off the ventilation systems but they did so before the pit was fully evacuated, which is likely to have resulted in many more casualties[2]. Japanese authorities allegedly prioritized rescue of Japanese workers near the openings to the pits[3]. Of the resultant casualties, only 31 were Japanese. Initial reports allegedly downplayed the scale of the disaster[4]; however there is little remaining evidence to prove or disprove these allegations. The source of ignition of the explosion has never been confirmed.

Andy Reid





Andy Reid's picture

The Chernobyl disaster is one of history's most infamous, a nuclear meltdown on the Russian site led to the evacuation and relocation of 350,000 citizens of Belarus, Russia and Ukraine as well as exposure of approx. 1000 staff and emergency workers to high-level radiation[1]. The estimated total casualty count ranges from up to 4000[2] to closer to 25,000[3] over time. There is speculation that most of the affected areas will continue to yield higher radiation-related cancer rates than elsewhere and ground zero remains uninhabitable[4]. The root cause of the incident is also still disputed but it is attributed to either human error[5] or design flaws in the cooling system[6]. A precise economic cost of the Chernobyl is impossible to quantify but estimates put it confortable into the region of hundreds of billions of dollars[7].


Andy Reid








Andy Reid's picture

A massive gas leak in India released 40 tonnes of methyl isocyanate into the atmosphere and led to the death of between 15,000 and 25,000 people in India[1] and injuries to 558,125 people of various severities[2]. The disaster has been attributed to poor working conditions, lack of maintenance and general disregard for employee and public safety[3] with a warrant being issued for the arrest the CEO, Warren Anderson[4] however the US government refused to extradite him for trial citing a lack of evidence[5] and even going on to blame the disaster on employee sabotage[6].


Andy Reid







Andy Reid's picture

A typhoon in the Henan province of China in 1975 resulted in the failure of the Banqiao Dam. The typhoon - Super Typhoon Nina - produced rainfall beyond the scope of design of the dam by over 3 times[1]. Estimates for the total death toll range from 170,000[2] to 230,000[3]. The estimated cost of the damage is $8.7bn[4] as flooding destroyed the homes of over 10 million people[5]. Although there were no direct legal ramifications for the Chinese government after the incident, it did spark a major campaign to repair, rebuild and update all the dams and reservoirs throughout the country, spending an estimated $9.7bn doing so[6].


Andy Reid







Ajay.Kale's picture

I work in offshore Oil & gas industry.
I have have seen no. of accindents happend in the various part of the world with energy related as well as non energy related.
Every accindents have their own immidate, specific or underlaying causes to happen it.
In our company we have policy 'GOAL ZERO' .It means zero accident in our working environment.
To minimise risk there are golder HSE rules which minimises risk to individual while working.

1)driving Safety (Wear your safety belt)
2)Work with valid work permit when required
3)Counduct gas test when required
4)Verify isolation before work begins and use the specified life protecting equipment
5)Obtain authorisation before entering a confined space
6)Obtain authorisation before overriding or disabling safety critical equipment
7)Protect yourself against a fall when working at height
8)Do not walk under a suspended load
9)Do not smoke outside designated smoking areas
10)No alcohol or drugs while working or driving
11)While driving, do not use your phone and do not exceed speed limits
12)Follow prescribed Journey Management Plan

Even though accidents happens ! Some time simply not adhering to the prescribed process.

The biggest ever disaster happend in oil & Gas industry on 6th July 1988, killing 167 men & with only 67 surviours.
The platform was completely distroyed.
The total insured loss was $3.4 billion.The  platform was producing almost 10% production of North Sea oil & gas production.
This plat form was producing around 125000 barrels of oil per day. in 1980 a gas recovery module was installed.
That was big impact on the oil & gas industry finacially 7 worst disaster in term of human live lost.

There were posible events happended to occur this disaster

Condensate Pump was under routine maintenance & maintenance was not completed within given time. The on-duty engineer filled out a permit which stated that Pump A was not ready and must not be switched on under any circumstances
After completion of shit on duty Engineer the on-duty custodian busy, the engineer neglected to inform him of the condition of Pump  Instead he placed the permit in the control centre and left.
 The fire-fighting system was under manual control on the evening of 6 July it should have been to automatic.
The safety valve within cindensate system was installed.
When pump started gas flowed into the pump & because of missing saftey valve produced overpressure.
Gas leaked out at high pressure & trigeering gas alrams befre anybody could act the gas ignited & exploded.
The desiged firewall was to resist fire 7 not explosion this failed here.

The major cause were lack of communication, inadeuate maintenance & safety procedure,process Design, & the various deviations used when origanilly it was oil platform & converted to gas.
The Cullen Inquiry was set up in November 1988 to establish the cause of the Piper alpha disaster.

Most significant of step was that the responsibility for enforcing safety in the North Sea was moved from the Department of Energy to the Health and Safety Executive

Banqiao Dam disaster
in China (Date:08-Aug-75, fatality-26000 immediate, 145000 after due to famine
and epidemic, 11 million people displaced)

San Juan LPG Tank
Explosion, Mexico (Date: 19-Nov-84, fatality: 500 – 600, 5000-6000 suffered various
degrees of burns)

  Chernobyl, Ukrainian
SSR ( Date: 26-Apr-86, fatality-56 immediate, 3944 after, 300000 people
displaced, cost-$7B)


Gulf of Mexico oil
spill/Macondo Blowout (Date: 20-Apr-10, fatality-11, 17 injured, cost-$20B)

Texas City Refinery
Explosion (Date: 23-Mar-05, fatality-15, 170 injured, Fined $21M. Another $87M
failure to correct safety hazards revealed in 2005)

Norco Refinery
Explosion, Louisiana (Date: 05-May-88, fatality-7, 42 injured, cost-$706M)

Fukushima, Japan (Date: 11-Mar-11,
fatality-1, 37 injured, fears/safety concerns with reactor # 4)

The Exxon Valdez oil
spill, Alaska (Date: 24-Mar-89, no fatality, crude spread over 11,000 square miles of
ocean, cost-$287M for actual damages and $5B for punitive damages)

Gannet alpha Oil leakage ( least 216 tons of light crude oil had escaped and at its peak the oil extended for 18 miles)

Mumbai high Oil fire (  11 fatality

Ike Precious C.'s picture

Wow. I've gone through these comments and I must confess these are insightful.

 1. Banqiao Dam Accident:

I never heard of the Bianqao Dam Accident until I registered with this website and blog. Having done some research on this accident, it indeed tops the chart of the Accidents in terms of number of fatalities and its impact on the country's economy.This will definitely go down as one of the most tragic because tit was a natural disaster and the Dam was designed based on the level of knowledge of the weather conditions of which there was a drastic change with time.

Another Cause of Accident, is failure to communicate to the Dam after a Request to open Dam has been granted because of existing flood in the downstream areas.

 2. Morvi Dam Failure in Gujarat, India, in 1979 where The Machchu-2 dam, situated on the Machhu river burst sending a wall of water through the town of Morvi, Gujarat India in.Estimates of the number of people killed vary greatly ranging from 1800 to 15000 people.

The failure was caused by excessive rain and massive flooding leading to the disintegration of the earthen walls of the four kilometer long Machchu II dam. It is still recorded as the Worst Dam Burst in teh Guiness Book of Records.

 3. Chernobyl Disaster, USSR: This occured when one of the reactors suffered a catastrophic power increase, leading to explosions in its core. This led to a large volume of radioactive fuel and core materials being dispersed into the atmosphere;this in return ignited the combustible graphite moderator that further increased the radioactive emissions. The accident occurred during an experiment scheduled to test a potential safety emergency core cooling feature, which took place during a normal shutdown procedure.

Apart from the 31 deaths (number stil disputed) recorded at the time of incident, the long-term effects were far more and affected a wide range of people from the firefighters to neighbours due to the radiaoctive emissions.

Investigations indicated that personnel error, operating procedures etc were major factors that led to this tragedy.

4. 1984 Bhopal Disaster in India: This was as a result of a leak of Methyl I socyanate gas and other chemicals from the plant that resulted in the exposure of hundreds of thousands of people. The accident was caused mainly by negligence of Safe operating procedures and poor working conditions. At least 2,500 died within the first 24 hours and according to other estimates (Wikipedia), 8,000 other deaths after 2wweks were attributed to the gas release.

Lack of functioning Safety valves and alarms led to the escalation of this tragedy because there was no indication that there had been gas releases.

When Legal action was taken against UCIL, there propsed for Settlement with figure of $350million with the capacity to generate $500-$600million within the next 20 years; but Activism rose up which led to prosecution of 7 of the workers, all indians, in 2010.

5.  Cleveland East Ohio Gas Explosion in 1944: This was as a result of leakage of gas vapours from one of the LNG storage tanks. The leaked gas mixed with the air and sewer gas combined to cause an explosion which wasn't taken very srious based on the fact that the Fire department were already taking care of the fire but another explosion on another LNG storage tank alerted everyone but was a bit late as the as/air/sewer mixture had entered homes through the sewer lines leading to a casualties from residents nearby the plant. At least 130 deaths occured on the spot.

Damages incurred ranged from $7million to $15million.

Ike Precious C.'s picture

6) San Juanico Disaster, Mexico, 1985: This was an accident that involved multiple explosions at a LPG storage facility caused by gas leaks at Transfre Site as a result of pipe rupture (as acclaimed by many) during transfer operations and led to accumulation and transfer of this gas through the wind towards the storage facility. This led to a spread of the fire to other LPG tanks and within an hour the fire had spread so much beyond control. 500-600 deaths and 5,000-7,000 serious injuries were recorded. a lot of houses were damged as a reulst of the explosion becuase the facility was surrounded by the town of San Juan Ixhuatepec with an estimate of 40,000 residents.

7) Piper Alpha Disaster, Aberdeen, 1988: This is one of the most terrible based on the timeline of the accident, extent of damage and number of fatalitites. Piper Alpha accident was caused by anoutburst of gas and explosion. This was as a result of lack of communication between shifts and improper handover information which led to lack of knowledge of the state of Pump A when Pump B had failed.

This led to the death of 167 men on the platform, drop in production (because Piper Alpha accounted for 10% of Oil and Gas produced in the North Sea), a total Insured loss of about £1.7Billion.

A major factor was the conversion of Piper Alpha to a Gas producing platform without upgrading safety measures to required level, such as replacing the Firewalls with Blast Walls.

8) Alexander L. Kielland Rig Accident, Norway, 1980: This the capsizing of a semi-submersible drilling rig that happened at the North Sea. This was as a result of a fatigue crack on the one of the bracings which held one of the legs of the platform.

This led to the death of 123 people out of the 212 people onboard. The accident was worsened when, due to a safety device/mechanism, some lifeboats refused to release.

The aftermath of the accident led to reorganization of command on offshore installations because, according to investigations, there was no effective commanad strcuture.

9) Aberfan Disaster, Wales, 1966: This was as a result of dumping mining debris close to a village and when heavy rains came, there came a sliding down of the piles of mining mixed with waterrushing down onto a village school and killed 116 children and 28 adults. This was attributed to as a natural disaster by the then chairman of the National Coal Board (NCB). This led to series of investigations and a fund-raising for the victims of the accident.

This accident led to many regulations with respect of dumping minig debris and changed the face of the Mining Industry worldwide.

 10) Deepwater Horizon Explosion, USA, 2010: This was caused by the release of gases from the well that rose up through the drill column and exploded afer bursting through numerous seals.  This happens to be the most recent, with low fatality rate with respect to others mentioned earlier and high legal consequences because of ignorance of the warning signals before the explosion that led to death of 11 crew members, 16 Injured release of high volume of hydrocarbons into the sea which led to death of aquatic life, and numerous environmental consequences, and total loss of the platform.

This has gotten BP paying $32.2billion for Oil spill clean-up and $20billion for victim compensation fund.   

Abiaziem Davidson's picture

Thousands of miners died from mining accidents each year especially in the processes of coal mining and hard rock mining and most of the deaths occurred in the developing countries. Benxihu Colliery which is located in china was first mined in 1905 and it started production of iron and coal under joint venture between Japanese and Chinese control.  Japan took complete control of the mine after invading northern part of china and introduced a harsh working condition and disease such as tyhoid and cholera thrived.

Benxihu Colliery disaster was caused by gas and coal-dust explosion in one of the shafts in the mine on April 26, 1942 and it sent flames bursting out of the entrance of the mine shaft entrance. Immediately after the accident, the Japanese guard erected an electric fence to keep relatives off from the site. In an attempt to restrain the fire underground, the Japanese guards shut off the ventilation and man-hole of the mine. Most workers underground died of suffocation and few actual killed by the gas explosion and not less than 1,549 workers were killed.

The physical cause of the disaster are poor working condition and inexperience personnel used in the mining operation  and most  of the miners were soldiers captured during the world war 2.
The underlying causes of the disaster are harsh and poor working condition.
The accident resulted in so many fatalities because there was no rescue procedure in place for the workers, there was no value for life and the only man-hole and ventilation hole were closed without complete evacuation of workers underground. This accident caused lots of hardship to the families that lost their loved ones in the accident.
Factors that contributed immensely to the escalation of this accident are the harsh / poor working condition and engagement of inexperience miners (most of the workers were captured soldiers).

Abiaziem Davidson's picture

San Juanico Diasater was an industrial disaster caused by a massive explosion at a liquid petroleum gas (LPG) tank farm in San Juanico, Mexico on 19 November 1984. The explosion consumed 11,00 cu, meters of gas, representing one third of mexico city’s entire liquid petroleum gas supply. The explosions destroyed the facility and devastated the local town of San Juan Ixhuatepec with 500 to 600 people killed and 5000 to 7000 others suffering severe burns [1]

The physical or technical cause of the accident was a gas leak on the site from a pipe rupture during gas transfer operation. The gas leaked from the ruptured pipe caused a plume of LPG to concentrate at ground level for 10 minutes and travelled with the wind to the west end of the site where the waste gas flare pit was situated. The plume got to the flare and ignited which resulted into a vapour cloud explosion that severely destroyed the tank farm and in a massive destruction of all gas tanks and equipments in the plant.

The underlying cause of the accident is ineffective gas detection system, poor plant inspection and maintenance.
The disaster resulted in so my fatalities and destruction of properties. The explosion destroyed large part of the town and ensuing fire with death toll of 500 to 600 people. Promises were made to assist the injured, rebuild affected homes and assist all the surviving victims but nothing has been done about it till date.

The factor that caused the escalation of the fatalities is ineffective gas detection system in the site. Most of the gas detector in the factory are either not working or in poor working condition and their reliability are not certain.  



Oluwatadegbe Adesunloye Oyolola's picture

Severe accidents in the energy sector occur as a consequence of industrial mishap. The degree of such accidents involves a significant hazard to people, properties and the environs. The list of unfortunate mishaps over time in the energy industry will not be complete without primarily addressing the industrial
accident that occurred at a BP refinery in Texas City. Its definition as a top severe accident is in accordance with the ENSAD database implementation.

Facts: - On March 23rd 2005, a fire and explosion occurred in an isomerization unit at BP’s Texas City Refinery resulting in deaths and injuries to 15 and 170 people respectively.

Physical/Technical circumstances that led to the accident: - Actions taken or not taken led to congestion
with liquid in the raffinate splitter, overheating of the liquid, subsequent over-pressurization and pressure relief. Hydrocarbon gushed to the blow down
drum and stack overwhelmed it. This caused liquid carry-over out of the top of the stack, flowing down the stack, accumulating on the ground, and causing a vapor cloud, which was ignited by a contractor's pickup truck as the engine was left running.

Main underlying causes: - The following reasons can be identified with the mishap; numerous failings in equipment, poor risk management, unprofessionalism in staff management, inappropriate working culture at the site, overdue maintenance and inspection, and anecdotal general health and safety assessments.

The accident resulted in (i) so many fatalities firstly because an alarm meant to warn about the quantity of liquid in the unit was disabled. Also because the hydrocarbon content in the surrounding air came down to the UEL, the truck provided the source of ignition for the Vapor Cloud Explosion.

(ii) so much harm to the environment because the particular type of disposal system serving the raffinate tower was a blow down drum with an atmospheric vent stack, rather than an inherently safer and more environmentally sound knock-out tank and flare system. The major factor that contributed to the escalation of the accident was the hot discharge passing through a heat-exchanger that pre-warmed incoming fluids.

Legal consequences of the accident: - BP was charged with a federal environmental crime were a US District Judge fined them with a US$50 million fine. Thus far, BP has paid more than US$1.6 billion to compensate victims.

Reference: -

Bassey Kufre Peter's picture

The top ten  severe accidents in energy sector are:

1. Warri, Nigeria  1998 OIL PIPELINE LEAK AND FIRE: On Saturday, October 17, 1998, around 1.00pm in a town  known as Jesse,  the principal town in Idjerhe clan in Warri, Delta State, in the Niger Delta  oil rich region in Nigeria,  a heavy sound like that of a burst truck tyre (Gboom!). The whole area was engulfed in flames. The fire explosion was from a leaking fuel  from an over aged  NNPC 16 inches  pipeline laid in the early 70s that ought to have been changed which runs from the community to the Warri Refinery. Over 500 people that went to fetch fuel from the leaked pipeline were burnt to death and over 6000 members of community were severely injured. The Jesse fire disaster is a true and practical revelation of acute poverty that the masses of Nigeria are immersed  in due to the continued misrule by successive military regimes in Nigeria. This led to a persistent and paralyzing fuel scarcity .

2. MACHHU- II, INDIA 1979 HYDRO-ELECTRIC DAM FAILURE: The failure is known as Morvi dam failure. It took place on August 11, 1979 in India. The Machchu –II dam, locataed on Machhu river burst sending a wall of water through the town of Morvi in the Rajkot district of Gujarat. The failure was caused by excessive rain and massive flooding leading to the distingration of the earthen walls of the four kilometer long Machhu II dam. The accident  about 2500 people killed.

3. 1975 BANQIAO, SHIMANTAN & HENAN, CHINA HYDRO-ELECTRIC DAM FAILURE:  At the beginning of August in 1975, an unusual weather pattern led to Typhoon Nina (Pacific hurricane) passing through Fujian Province on the coast of South China continuing north to Henan Province dumped almost 18 inches of rain into the basin in 24 hours, exceeding the yearly precipitation rate, collapsing buildings and destroying thousands of villages. This led to the killing of 30,000 people at the immediate and 230, 000 total.

4. 1989 THE ASHA-UFA, SIBERIA LPG PIPELINE LEAK AND FIRE: The disaster took place on June 4, 1989 at 1:15 (local time) close to the cities of Ufa and Asha  in the Soviet Union on the Trans-Siberian Railway. A Liquidfied Petroleum Gas(LPG) explosion killed 575 people and wounded over 600. The accident was cause by two trains passing each other threw sparks near a 1km leaking pipeline. The explosion was so serious that it blew of windows in Asha, eight miles away.

5. 1984 CUBATAO BRAZIL OIL FIRE ACCIDENT: The accident took place on the February 25, 1984. An oil spill set the shantytown- Vila  Soco on fire, killing with a death toll of 508. The oil spill was cause by a leaking pipeline and this resulted in a serious pollution. Hard providence were taken to diminish the pollution in the city, costing $1.2 billion so far.

6. 1984 Mexico CITY LPG EXPLOSION: The occurred on 19 November, 1984 at  a government owned and operated LPG terminal known as PEMEX LPG Terminal at San Juan Ixhuatepec, Mexico City. It killed 500 people and the terminal destroyed.

7. 2010 MACONDO EXPLOSION: On April 20, 2010, catastrophic event took place at the rig located at the Gulf of Mexico. A blow out occurred and this led to an explosion and the rig got engulfed with fire. The blowout led to the killing of eleven (11) people, loss of the regional tourism, fishing industries, damage to wildlife, environment and the rig sank. This led to the permanent sealing of the well by BP. 

8. 1988 PIPER ALPHA OIL RIG ABLAZE: On July 6, 1988, a North Sea oil production platform operated by Occidental Petroleum experienced an explosion that resulted in an oil and gas fires destroying 167 men with 61 survivors .The total insured loss was about £1.7 billion.

9. 1992 KOZLU, TURKEY COAL MINE METHANE EXPLOSION: The occurred at 8 P.M  on Tuesday 1992 at Kozlu, in the Black Sea coal-mining area of Zonguldak  killing 272 workers abd with 87 injured survivor.

10. 1990 DOBRNJA-JUG YOGOSLAVIA COAL MINE DISASTER: This occurred on the 26 August 1990 near Tuzla, Bosnia and Herzegovina at Dobrnja-jug when a methane gas explosion 1,800 feet below the surface  caused a cave-in which buried the entire third shift who were near the site of explosion killing 180 miners , destroy assets with on one survivor.












Bassey, Kufre Peter
M.Sc-Subsea Engineering-2012/2013
University of Aberdeen.

Abiaziem Davidson's picture

Safety in the operation of chemical plants where toxic gaseous substances are handled is of prime importance. Safety aspects begin right at the stage of designing a chemical plant. Bhopal disaster is recorded as one of the world worst industrial disaster which occurred in india as a result of gas leak (Methyl isocyanate) on night of 2nd to 3rd of December 1984 at the Union Carbide India Limited (UCIL) pesticide plant in Bhopal, Madhya Pradesh.

The physical circumstances that led to Bhopal disaster: Toxic gas leaked into the Bhopal’s atmosphere and this was due to water along with catalytic materials such as iron entering the storage tank 610 of the union carbide MIC plant. The exothermic reactions began and within an hour, it turned into violent runaway reactions resulting in a high pressure and temperature in the tank. The reaction products and the unreacted MIC in the tank finally got into the atmosphere through the vent line. The Technical circumstances that led to Bhopal disaster: Union Carbide India Limited has a very poor maintenance culture, most of the safety equipment was either in poor operating condition or they were completely out of operation. Previous fatal accidents, near-miss incidents and recommendations were not looked into, Warning system for Bhopal community was not activated during the incident, fire and rescue (emergency squad) members were not qualified and trained to handle such incident, there was no senior experienced supervisor on the night of the incident.

The underlying causes of the incident summarily are: Poor engineering design of the chemical plant, location of the chemical plant (the plant is ought to be located far away from community dwelling are), use of inexperienced personnel for chemical operation, poor maintenance culture, non-commitment to safety standard and inefficiency of the regulatory body to audit and regulate activities of chemical establishments.

Bhopal accident recorded highest industrial fatalities because there was no awareness, drills or training on how to handle such an accident. Bhopal community literally did not understand what Methyl isocyanate gas was, where to get treated if the gas is released to the atmosphere and how to manage the incident if occurred. Secondly the gas leaked into the atmosphere in the night making it difficult for people to evacuate the area immediately. Lastly community warning alarm was not activated and no instruction was given to the community on the situation of things on ground and what to do (most workers on duty were not affected because they were instructed to remain indoors and this same instruction was not passed to the community).

Tested conducted in 1989 revealed that soil and water samples collected near and inside Union Carbide India limited were toxic to aquatic life, polluted underground water and soil for farming.

The legal proceedings faulted Union Carbide India Limited on its lack of commitment to safety and there was an out of court settlement reached in 1989 amounting to US$470 million for damages caused in the disaster. The Bhopal disaster caused the end of Union Carbide India Limited in the chemical industry.





Mark Haley's picture

I have gone through all the posts in this thread and created the table below with the major incidents after 1950 for which I could find financial information (during my search I found hundreds more incidents that could be added to this list).  While these have been listed in order of number of casualties this could equally have been done by the cost of the accident.  I have also added another column for the long term cost to the environment and the impact for future generations?  Please note some of the ‘costs’ and ‘years to return the environment to previous state’ are the best estimates I could find or educated guesses from the information available and may not be totally representative but are hopefully enough to prove my point.


With the above information how do we decide the order of severity.  The human side of us would say ‘leave the list in order of casualties’ as life is more important than anything else. 

However, in risk management it is not that easy, as we have to quantify it by putting a price on it, even putting a price on a human life!!  If we do not then H&S legislation would insist that everything is 100% safe and that we could not use ALARP when considering safety procedures and engineering practices would become prohibitively complicated.

So what is the price of a life??  Depending on where you read this, it can be between $5 million and $10 million USD.  Additionally, this can vary depending on nationality and this would also vary on the year you were discussing.  However, for arguments sake I have used the figure of $5 million for my calculations.

We also have the difficult question – what is the dollar value of the environment??  This is extremely subjective and open to a whole new debate and involves extremely complicated calculations on what kind of natural resources would be lost.  I don’t have the time or numbers to carry out these calculations so I have just used my opinion instead to weight the above list.

As you can see this result draws some interesting conclusions, in that, in risk management terms Fukushima with no lives lost is higher than the Bhopall disaster with ~4000 lives lost!!  But it also follows what most comments have said in that the Banqiao disaster is definately the worst. 

Henry Tan's picture

Superb job!

SanjayVyas's picture

I agree to Mark Haley's explanation on severity of an accident. He has considered number of deaths and damage to environment and cost associated with both the key aspects of an accident. I think injuries (both short term and long term) should also be considered in assessing the severity of an accident. IAEA and ENSAD both define “Injured” under their list of Damage Categories with a minimum number of >10.   The MIC poisoning of Bhopal, India had many disastrous consequences. Hundreds of thousands of people were injured and around 15,000 died. A government affidavit in 2006 stated the leak caused 558,125 injuries including 38,478 temporary partial injuries and approximately 3,900 severely and permanently disabling injuries

Other consequence indicators defined by ENSAD are Evacuees, Extensive ban on consumption of food, Release of hydrocarbon, Enforced clean up of land and water area and economic loss.

Sanjay Vyas- (51234203)

Abiaziem Davidson's picture

Nambija Mine Disaster was cause by a landslide which occurred in an isolated mining settlement in the southeastern part of Ecuador on May 9th, 1993. More than 300 people at the mine site were buried alive as part of the mountain above the mine site gave way.

The cause of this disaster is poverty, lack of safety procedure in mining, lack of government regulatory agency and natural disaster. Nambija community is located in a valley, 2600m above sea level; most of the houses are built right on the tunnel entrances to the mine and each family had their own mine, mine shafts were hitting other mines, even basic principles of static went unobserved.

The underlying cause of this disaster was the working and living condition the people of Nambija found themselves in. The advice of an expert was not adhered to and the site is difficult to access.

The settlement arrange of the community is the main reason that escalated the death toll of this disaster. This is caused by high poverty level in the country. The people of Nambija sees the disaster as part of their life and no plan to improve on the living condition. 


Abiaziem Davidson's picture

The garment factory is located in Baldia town of Karachi and its main operation is exporting of garments to Europe and the United State and had between 1200 to 1500 workers. The factory caught fire when a boiler exploded and the flames ignited chemicals that were stored in the factory. More than 300 workers were inside the factory when the fire erupted, most exit doors were locked and many windows were barred with iron which made it difficult for workers to escape at the time of the fire and consequently many of the deaths were caused by suffocation.

The main technical cause of the disaster is the explosion of the boiler and the underlying cause is the poor design approved and used in building the factory, shutting of all exit doors and windows during operation and failure of the safety and industry regulatory body to inspect the factory.

Shutting of all the exit doors and windows contributed immensely in the disaster death toll, most of the workers dead as a result of suffocation. With all doors and windows covered with iron bars, it will be difficult to open them during emergency of any nature.

Harsh working condition and no emergency exit route are some of the factors that escalated the death toll. 

The cause of this disaster is still under investigation and the owner of the factory has fled the country but promised to compensate all victims of the disaster accordingly. 


Mark Haley's picture

I touched on this in my previous thread but I would like to expand a bit more on it.  When managing risks we now have to think much more about any subsequent impact on the environment and associated costs.

This is especially prevalent when it comes to Oil and Nuclear disasters, as the effects are felt for many years after, and the costs wrt managing these can be extremely high. 

Therefore, when calculating risk of possible disaster scenarios we must take into account the ~$5million per life lost, the cost of injuries, compensation and loss of assets, clean up costs and the long term cost to the environment. 

In many evolving economies we have seen the mentality of ‘growth at any cost’.  With this growth and the need for more energy, the dollar value of the loss of natural resources has not always been considered.[1]  However, if we were to consider say, the price of losing clean water or large areas of forest before undertaking a project to exploit energy resources would we still continue?

The difficulty for us, is how do we quantify the environment and factor it into our risk management modelling??

In conventional economics it is generally accepted that measures of economic value should be based on what people want; and that individuals, not the government, should be the judges of what they want. Additionally, perception and human factors play a huge part in this cost analysis.

Looking at one example from the previous post, Chernobyl, which is still placing a huge burden on national budgets of the governments of Russia, Ukraine and Belarus.

In Ukraine, 5–7 percent of government spending each year is still devoted to Chernobyl-related benefits and programmes. In Belarus, government spending on Chernobyl amounted to 22.3 percent of the national budget in 1991, declining gradually to 6.1 percent in 2002. Total spending by Belarus on Chernobyl between 1991 and 2003 was more than US $13 billion.[3]  Since the Chernobyl accident, more than 330 000 people have been relocated away from the more affected areas, and the government are still trying the raise the $1.1 billion to create a sarcophagus to enclose the destroyed reactor.  Additionally, there are 5700 acres of forest that were seriously contaminated with Sr-90, Cs-137 and Pu-239.  With approximately 30-year half-lives for the first two isotopes it means that it will take nearly three centuries before they have decayed to safe levels, and Plutonium-239 has a half-life of 24,100 years so it will be many millennia before it is safe.

Therefore, a small part of the planet has effectively been permanently removed for human habitation with the continued poisoning of ground waters and plant/animal life.

The total economic cost to just Russia, Ukraine and Belarus so far is $500 billion (not including the rest of the world) and the costs will continue for some time yet.

Therefore, when calculating risks it is imperative to consider these types of disaster scenarios so that the cost of safety measures and backup systems are justified compared with a long term cost of supporting a large part of the population and containing a radioactive poisoned landscape.[4]

 I would like to open the following question for debate: How would you put a dollar price on an environmental resource when calculating disaster risks?  





 Mark Haley

Leziga Bakor's picture

In order to rank accidents in terms of their severity, a base for comparison must first be chosen. In my view accidents severity should be based on the number of serious injuries and fatalities. Over the years, there have been several accidents in the energy sector. I will attempt to rank them in order of their severity in terms of number of fatalities and deaths.
1. The first is the collapse of a dam in china. As a result of poor construction of a dam in china, in 1975, the dam collapsed when there was a heavy rain and killed over 100000 people. Another 150000 people died later as a result of epidemic diseases and famine cause by the accident. The total number of deaths was recorded over 250000.
2. The second most severe accident in the energy sector is the piper alpha disaster in 1986. In a platform in the North Sea, there was an explosion and fire.  This resulted in the death of 167 men and a loss of about USD $3.4 billion.
3. The third most severe accident is the sinking of a mobile offshore oil rig in 1982. The oil rig ocean ranger was struck by a wave off the coast of Newfoundland in Canada and it sank and killed its 84 crew members.
4. The fourth most severe accident is the Chernobyl disaster in 1986. In a nuclear plant Chernobyl in Ukraine, a test on one of the reactors went out of control and it resulted in a nuclear meltdown. The resulting steam explosion and fire killed up to 50 people. It is also estimated that there may be between 4000 and more additional cancer deaths that resulted from the accident over time. The town where the accident occurred is now a ghost town and the area remains poisoned till date.
5. The fifth most severe accident is the explosion of an oil refinery in 1984. In Romeoville, Illinois, there was an explosion in union oil refinery and 19 people were killed.
6. The sixth most severe accident is the Texas City refinery explosion in 2005. There was an explosion in a BP refinery in Texas. The explosion resulted in the death of 15 people and left over a 100 injured. The accident occurred because several leading indicators failed to perform their duty. This lead to a leakage and a running diesel truck set off the explosion.
7. The seventh most severe accident is the deepwater horizon oil spill in the Gulf of Mexico in 2010.  In this accident, the oil that was spilled is considered to be the largest spill in the world. There was an explosion due to the escape of HPHT gases from the reservoir at uncontrollable rate. The BOP failed to work properly and could not stop the gas from rushing to the platform and causing an explosion. 11 people died on the platform and there was a massive oil spill.
8. The eight most severe accident is the Shell oil refinery explosion in 1988.  There was a corroded pipe in the catalytic cracker. This pipe was ignited after hydrocarbon gas escaped form the pipe and this lead to an explosion. Seven people were killed and 42 injured. 2800 people were evacuated from the neighbourhoods nearby.
9. The ninth most severe accident is the Connecticut power plant explosion in 2010.  The plant was still under construction and there was an explosion in the plant. This lead to the death of 5 people and 27 people were injured.
10. The tenth most severe accident is the San Juanico disaster. There was an explosion in a liquid petroleum gas farm and it killed several people and injured many.
These are my top 10 severe accidents in the energy sector ranked according to the number of fatalities.
Major source: date accessed 16/11/2012.

Justice J. Owusu's picture

I have read through all postings on the subject and I agree with Mark’s first submission to some extent, but it is very difficult to price human life or a permanent damage to the environment. The most severe incident should not be limited to the number fatalities resulting directly from the incident. I think both the short and long term effects of the incident on human lives, environment and property should be the basis of ranking incidents. For example, an incident that may result in severe social or psychological impairment that may cause people to commit suicide is a serious as multiple fatalities occurring from that incident.  Also, if the incident leads to severe damage to or pollution of the environment in such a way that it affects generations after the incident has occurred, it must have the same order of severity as one that results in multiple fatalities.


Dear Colleague,

I've went through all the comments and I do agree from the official sources, it is accurate enough to quantify these disaster by criterion set forth but after Mark's table shows, it do changes my view.

Here's why:

1. The criterion is only an objective approach.

2. It did not take long term effects into consideration.

3. It do have certain level of biases.

4. It narrow to cost and death when other factor were not put forth. 


Let me give an example in point order:

1. In Chernobyl Case, the early detection of radioactive leak was by personnel in Sweden Nuclear power plant that assume it was a leak from thier own plant.

2. The whole city of Pripyat, Ukraine was displaced and still unhabitable due to dangerous dosage of radioactive level still present.

3. Countless people in Ukraine and in Europe has been exposed to radioactive dust for some extend time after the blast before the official announcement were made.

4. The manifestation of radioactive poison could be observe in two level. High exposure : immidiate symptoms including vomitting, skin burn and event death , Low Exposure:  thats the tricky part, unborn baby got mutated and borned with defects and the gene continue down the line



How could we quantify this? The direct consequences of death immideately is one way but how about the death due to these in 50 or 100 years to come? A qualitative approach should be develope from all side of the industry. Event in Chernobyl still leave the evidance of what could happened if disaster were to happened. 

At some extense, real data are not share by the guilty party and the overall report produced in an understatement due to some restriction. For instance Fukushima Daiichi incident, who's to say that there are no long term effect to quality of life, environment, economics and political, when not 1 but 3 meltdown with substantial radioactive dust burst into athmosphere from the safest nuclear power plant ever to be build? And through basic chemistry and physics theory we know the decay rate of such element could takes decade to reach its half life.



 1. International Nuclear Safety Advisory Group (1992), INSAG-7, The Chernobyl Accident: Updating of INSAG-1, International Atomic Energy Agency.

2. Incident and Emergency Centre (September 28, 2012), Status of the Fukushima Daiichi Nuclear Power Plant and related environmental condition, International Atomic Energy Agency.

3. Independent Investigation Commission (2012), The official report of The Fukushima Nuclear Accident Independent Investigation Commission, The National Diet of Japan.

4. International Atomic Energy Agency, The International Nuclear and Radiological Event Scale (INES)Information Series / Division of Public Information, 08-26941 / E. 

5. Thompson, J. (Producer). The Battle of Chernobyl [Documentary], Play Film.


Patricia Fleitas's picture

Dear anasabdrahman,

I completely agree with your point of view, rank the top ten accidents as our colleagues done is out of analysis due to it is very subjective to the information available in public sources and your own individual criteria. A good approach to analyze severe accidents in the energy sector is done by Hirschbersg S. Et al (1998) where a complete analysis using a sub-classification gives a better measurement of the severity of the accident. This is the sub-classification used:

• Severe accident by immediate fatalities
• Severe accident by injured per event or per energy unit produced
• Severe accident by evacuations per event or per energy unit produced
• Severe accident by economic losses
Using the sub-classification pointed out by Hirschbersg S. Et al, Nuclear accident can be measured using the economic losses sub-classification, and in fact comparing with the rest of the energy sources (coal, gas, oil, hydro) the Chernobyl accident reached around $18Billion and is likely to extend with the construction of the new confinement. But, I could suggest to measure nuclear accidents by Sub-consequences including the economic affection, psychological damage and health quality of the 9,000 to 33,000 people that could die over the next 70 years, due to the high dose of radiation received. The problem is the human effort that you need to put to quantify it for a long period of time.

People realized about the increase in cancer rates in our community. Don’t you think that all these accidents are the result of our poor health condition?.  Potentially, every discharge of produced water from offshore platform is introducing dissolved compounds that aren't biodegraded ren’t biodegraded by the environment and affects the fishes which later we eat because is healthier than beef. So, what could be the sub-consequences over time of Horizon oil Spill that is not to public?  

 Hirschbersg S. Et al (1998). "Severe accidents in the energy industry". 1st edition. Aul Scherrer Institute.

Tianchi You's picture

1.Chernobyl nuclear accident.

April 26, 1986, Soviet Ukraine's Chernobyl nuclear power plant serious leak and explosion, resulting in the largest-ever nuclear disaster. Radioactive substances pollute the air, food sources and groundwater, a few years after the accident, the local people died of cancer, and this effect will last for decades.

2 Kingston power plant collapsed accident

As many as 600 coal power plants in the United States, many power stations are casual thick layer of ash piled up in the ash pond.

December 2008, in Kingston, Tennessee, United States power plant collapsed, ash permeates the air, destroying a number of houses, land and rivers contaminated, and accumulated a lot of mercury, killing wildlife.

3. Persian Gulf oil spill

The world's largest oil spill occurred in the Gulf War in 1991. Saddam deliberately dumped into the Persian Gulf up to 100 million gallons (about 3785.4 cubic meters) of oil, causing massive deaths of local birds and fish.

4 the Love Canal incident

Love Canal is located in California, a century ago, a canal dug for the construction of hydropower stations, dried up in the 1940s was abandoned. In 1942, an electrochemical company purchased about 1000 meters long abandoned canal, dumping large quantities of industrial waste as rubbish warehouse, lasted 11 years. 1953, this canal full of toxic waste landfill coverage is good turn donated to local education agencies. Since then, the City of New York in this land continue to develop real estate and constructing a large number of residential and a school.

Beginning in 1977, residents here continue to occur to all kinds of strange diseases, pregnant women, abortion, child mortality, birth defects, epilepsy, rectal bleeding, and other symptoms also occur frequently. In 1987, the ground began oozing black liquid containing a variety of toxic substances.

5.India Bhopal gas accident

In 1984, one of India's Madhya Pradesh capital of Bhopal pesticide plant gas tank valve failure, a large number of toxic gas leak, causing 1 million deaths. The wounds left by the Bhopal disaster long in people's heart ache, sounded the alarm of industrial disasters.

6. Piper alpha disaster in 1986. In a platform in the North Sea, there was an explosion and fire. This resulted in the death of 167 men and a loss of about USD $3.4 billion.

7. Aberfan Disaster, Wales, 1966: The Aberfan disaster was a catastrophic collapse of a colliery spoil tip that occurred in the Welsh village of Aberfan on Friday 21 October 1966, killing 116 children and 28 adults.

8. 2010 BP oil spill :It is the largest accidental marine oil spill in the history of the petroleum industry.The spill stemmed from a sea-floor oil gusher that resulted from the 20 April 2010 explosion of Deepwater Horizon, which drilled on the BP-operated Macondo Prospect. The explosion killed 11 men working on the platform and injured 17 others.It does not only effect the economy, ecology , tourism and fishing, but also change US and Canada's policies on drilling and Health and Safety. However, even though BP has tried to slove the problems, but it is unchangeable in some cases.

9.2011 Japan Fukushima nuclear disaster: March 11, 2011, off the northeastern coast of Japan a major earthquake and tsunami, Japan's Fukushima Daiichi nuclear power plant at the same time lead to a nuclear accident. This is the worst nuclear disaster in the world since the 1986 Chernobyl nuclear accident. After the loss of electricity supply, seawater destroyed vital back-up generators, cooling system failure, unable to control the nuclear fuel decay heat. Within a few hours, the hydrogen continued to gather and exploded external containment bombed, three partial meltdown of six reactors. After the accident, the workers began rescue operations for several weeks, trying to control the Fukushima nuclear power plant.

Fukushima nuclear accident not only changed the face of Japan's energy, but also have an important impact on other countries in the world, long-term energy plan. In early 2011, nuclear energy was considered at the beginning of a renaissance, with the Fukushima nuclear accident, nuclear renaissance of the road is to step on the brakes. A few days after the tsunami, Germany shut down eight of the 17 nuclear power plants, and soon after decided to close all nuclear power plants before 2022. European engineering company Siemens, said in September, will withdraw from the nuclear power plant market. The voice of protest against the construction of the world's largest nuclear power plant plan after the Fukushima nuclear accident, India appears more and more high, but the Indian government insists that the construction of nuclear power plants to meet the growing demand for electricity and reduce greenhouse gas emissions must be taken.

In late 2011, the situation of the Fukushima nuclear power plant to stabilize, but Japanese officials are still facing a series of challenges, such as the reactor's radioactive decay and how to deal with the danger outside the quarantine area. In October, the International Atomic Energy Agency to send radiation experts to Japan to check the No. 3 reactor.

I think we can not rank which one is the first or second, all of them are tragedies on human-being's history. We not only need to have sympathy on the people and countries who suffered from those disasters ,but also need to improve people's awareness on health and safety,especially emphasis on the management of construction.





Patricia Fleitas's picture

Searching about severe accidents and using the definition explained by Leighmoreton (2012), I found quite curious about the safety record of my country. Surprisingly, I found that the worst oil tragedy of Venezuela took the life of more people that Piper Alpha; however, a complete analysis about the causes of the accident, safety measurements, legislation to avoid in the future such as the    “Lord Cullen’s public inquiry” is not available. In addition, only information from the newspapers of that time is available in Spanish.  This is the analysis of this research:

TACOA Power plant, 1982. Venezuela

Final consequences: between 150-180 people die and severe destruction of assess of the community around and terminal.
Physical/technical circumstances that led to accident: during the discharge of fuel oil from the ship to the terminal, a overheating was detected. The employee opened the hatch of the ship storage tanks and allows the factors required for an explosion (oxygen+fuel+heat). The explosion reached the storage tanks on land. Only the employees in the terminal died.
Underlying causes: Boilover of the land storage tanks produced the second explosion, five hours later of the first explosion. Another causes: foam fire extinguishing system fail, corrosion in the valves of emergency water system and lack of emergency power generation of the emergency water pumps. Poor design of access roads to allow the fire trucks to access to the source of the fire.
Why did the accident result in many fatalities and/or environment harm: Lack of a procedure for evacuation, escape and rescue. Management supervision to ensure the integrity of the installations. The community living around the plant area went to the plant to see the consequence of the first explosion.
Factors that contributed to the escalation factors: All the security emergency mechanics fails due to lack of maintenance and poor design. The accident started early in the morning and the community concentrated near the accident. Lack of supervision to establish a perimeter security area to avoid people concentrates around the installations.
What are the legal consequences of the accident: It is difficult to determined due the installation was owner by the government. However, after the accidents new safety framework and polices where developed, such as: integrity and supervision of installations, security perimeter area definition, installation of fire and gas detection system, information of the community about hazards and emergency evacuation, among others.  

• Tragedia de tacoa. Access on 27/11/12.
• Rondon E. “Tacoa”. Access on 27/11/12.

Tianchi You's picture

I give this title as a kind of supplement of the former post. In
my opinion, we should not rank a disaster easily ; however, I still think
Banqiao Dam and Shimantan Dam disaster is the first disaster on modern times
history. As I am a Chinese, this disaster happened in China but a lot of people
have no idea about it. This disaster happened in 1975 because of the heavy
rainfall resulted in flood. Extreme rainfall beyond the planned design
capability of the dam. It is the worst dam failure with more than 100,000
dead.Actually it may result in 270,000 falities. In my personal opinion, this
tradegy happened because of several reasons: 1. It was constructed by Former
Soviet and Chinese government, the technology of dam construction in 1950s was
not mature enough. 2. The evacuation was main reason, people were not informed
ASAP. 3. The failure of the government on that time, this is hard to say but I
think the government on that time had its failures.

This disaster happened near my province in China, it happened
25years before I was borned. After that, the famine happened in that province
so a lot of people moved from their hometown to other provinces ( my hometown
city is one of the places which they moved to ).

These dams, which collapsed mainly, affected the local population.
According to the records nearly 26,000 people died because of flood and nearly
145,000 people died because of famine and epidemics. Nearly 5,960,000 buildings
collapsed and 11 million residents were affected. Many were injured. This
converted China into a land full of corpses.





Tianchi You   


Oil&gas engineering

Kingsley ENEM's picture

The banqiao dam was constructed in 1950s on Ru River as part of a huge development to control flooding and produce electricity in central China. The design parameters for the dam was 118 meters high (387 ft) with storage capacity of 492million m3 (398,000 acre feet) and had a reserved for flood storage of 375 million m3 (304,000 acre feet). As soon as the construction of the dam was over, little cracks appeared along the sides of the dam and sluice gates due to construction and engineering errors. However, the cracks were repaired with the advice from Soviet engineers, and the structure was considered safe and unbreakable. The new design of the dam (after repair) also got a nickname - the Iron dam.
Banqiao dam was designed to survive a 1-in-1,000 year flood. In August 1975, Typhoon Nina occurred and dumped nearly 8 inch of rain into the basin in 24 hours, beyond the yearly rainfall rate. The sluice gates were unable to handle the excess flow due to sedimentation blockage. In the early morning of August 8, the smaller Shimantan dam, that was designed to survive a 1-in-500 year flood failed to handle two times its storage capacity and broke upstream. In some minutes later, water crested at the Banqiao dam and it too failed. This swiftly triggered the failure of 62 dams in total.
The resulting flood waters produced a great wave several meters high to rush downwards into the plains below at almost 50 kilometers per hour, thus creating temporary lakes as big as 12,000 square kilometers. Seven county seats (Suiping, Xiping, Pingyu, Xincai, Luohe, Linquan) were flooded, none of which had time for evacuation. The Beijing-Guangzhou Railway, a key channel, was cut off, and other communication infrastructures were destroyed. Also, epidemics and famine devastated the trapped survivors. Almost two weeks after the incident, millions of people were still trapped by the waters, relying on airdrops of food and inaccessible to disaster relief.
The information of death recorded by Hydrology department of Henan Province was approximately 26,000 people from flooding and another 145,000 died during subsequent epidemics and famine. Furthermore, about 5,960,000 buildings collapsed and 11 million residents were affected.


Kingsley ENEM's picture

On April 25, 1986 one of the worst nuclear accidents in history took place in at Chernobyl, Ukraine as an outcome of unauthorized safety test. The workers at reactor No. 4 planned to test whether the turbines could produce enough electricity to keep the coolant pumps running in the occurrence of a loss of power until the emergency diesel generator was activated. In order to avert the test run of the reactor being interrupted, the safety systems were intentionally switched off. The reactor had to power down to 25 per cent of its capacity for the test. This technique did not go according to proposal: for strange reasons, the reactor power level dropped to less than 1 per cent. The power consequently had to be slowly increased. Thirty seconds after the start of the test, there was an abrupt and unanticipated power surge. The reactor's emergency shutdown which should have stopped the chain reaction failed. In a little time interval, there was a huge increase in temperature and power level. The reactor went out of control. There was a fierce explosion. The 1000 tonne sealing cap on the reactor structure was blown off. The fuel rods melted at temperatures over 2000oc. The radioactive fission products released during the core meltdown were sucked up into the air.
The government of Soviet recorded 31 deaths while trying to put off the fire. In addition, 600 others fell victim to severe radiation sickness; some have died and the rest suffer from long-term illnesses. Other people in the community estimated 4,056 deaths. One week after the explosion, 150,000 people living within the reactor were relocated and several may never be allowed to return home. A new Greenpeace report has shown that the Chernobyl disaster could be liable for more a quarter of a million cancer cases and closely 100,000 cancer deaths

Furthermore, assisting the clean-up were 100,000 troops and 400,000 civilians, called "liquidators". Several of them wore masks at first, but then "forgot about it". Hunters were ordered into the region - all animals in the area, including domestic animals were killed to prevent the contamination from spreading.

Environmental damage was extensive instantly following the accident, spreading from fauna and flora to rivers and lakes and all the way down to the groundwater. The amount of the harm led scientists and government officials to the decision that the Chernobyl exclusion zone had been exposed to enough radioactive effect to severely change the ecological balance of the region for decades. This initial assessment could not be farther from the truth as wildlife abounds in even the most affected areas of Chernobyl no more than 20 years after the disaster.



Kingsley ENEM's picture

The Piper alpha was a North Sea oil production platform operated by Occidental Petroleum (Caledonia) Ltd. It was built at McDermott's offshore construction yard. Piper Alpha accounted for about ten per cent of the oil and gas production from the North Sea at the period. It started production in 1976 as an oil production platform but was later upgraded to process gas.
In July 1988, work started on one of two condensate-injection pumps, labeled ‘A' and ‘B', that are used to compress gas on the platform prior to transport of the gas to Flotta. A pressure safety valve was disconnected from compressor ‘A' for recalibration and re-certification and two blind flanges were fixed onto the exposed pipework. The dayshift team then ended for the day.
In the evening of 06 July, pump ‘B' tripped and the nightshift team agreed that pump ‘A' should be brought back into service. The pump was set operational and there was a gas leak from the two blind flanges. At about 2200 hours, the gas kindled and exploded, triggering fires and harm to other areas with the additional release of gas and oil. Few minutes later, there was a failure at Tartan gas riser thus causing a second major explosion with extensive fire. An hour later, the MCP-01 gas riser failed causing a third major explosion. The platform was engulfed by fire and that led to the collapse of the platform structures and installation.
The accident killed 167 men and only 62 survive. Total insured loss was $3.4 billion while the environmental damage was very severe resulting to pollution in North Sea. It remains world's worst offshore oil tragedy in terms of lives lost.

Kingsley ENEM's picture

The MV Dona Paz was a Philippine -registered passenger ferry that sank after colliding with the MT Vector on December 20, 1987, with a possible death toll of 4,375 people. The accident resulted in the deadliest ferry disaster in history.
The ferry was built in 1963 by Onomichi Zosen of Onomichi, Hiroshima, Japan and was first called Himeyuri Maru. She had passenger capacity of 608 people when it was plying the Japanese waters. A Filipino operator of a fleet of passenger ferries (Sulpicio Lines) bought the ferry in 1975. Sulpicio Lines changed the name again to Don Sulpicio, and later, the Dona Paz.
In December 20, 1987, the Dona Paz came ashore from Tacloban City, Leyte, for the Philippine capital of Manila, with some stopovers around Catbalogan City, Samar. However, later reports showed that Dona Paz had no radio. As at 2230H, Philippine Standard Time, The ferryboat was positioned at Dumali point, near Marinduque. The weather at the sea was clear and cool but the sea was rough. However, some of the passengers were sleeping when the Dona Paz collided with MT Vector, an oil tanker on its way from Bataan to Masbate. About 8,800 barrels of gasoline and other petroleum products owned by Caltex Philippines was carried Vector.
The result of the collision ignited Vector‘s cargo and fire began on the ship and later spread onto Dona Paz. The flames spread swiftly throughout the ship causing the lightings to go off. Unfortunately, there was no life vest found on Dona Paz. There was serious panic between the passengers and the crew. The crew were not giving orders or made attempt to organise the passengers. Shortly, the ferry began sinking; some of the passengers were burned and most passengers jumped into the sea (shark infested water).
Accordingly to the announcement made by Sulpicio lines, the official passenger manifest of Dona Paz recorded 1,493 passengers and 60 crew members on board. Later findings showed that Dan Paz was overcrowded with passengers. Survivors claimed that it was likely that the Dona Paz may have accepted as many as 3,000 to 4,000 passengers; as some passengers were seen sleeping along corridors, on the boat decks with three or four persons on them.

Kingsley ENEM's picture

The Courrieres mine disaster occurred on the 10 March 1906 in northern France. The Courrieres Colliery in northern France was a challenging series of mines near the Pas-de-Calais Mountains. Tunnels into the mines issued forth from various cities in the area and more than 2,000 men and boys worked the mines, digging for coal that was used mostly in the production of gas.
On March 9, a fire started 270 meters underground in what was recognized as the Cecil pit. The workers couldn't immediately extinguish it, so they blocked the pit's outlets and starve the fire of air. A huge blast was heard shortly by 7 a.m. on the morning of Saturday 10 March 1906. An elevator cage at Shaft 3 was thrown to the surface, destroying pit head workings; windows and roofs were raged out on the surface at Shaft 4; an elevator cage raised at Shaft 2 contained only dead or unconscious miners. Apparently, flammable gases came in through the cracks in the pit's wall that ignited the still-smouldering fire.
Fires fumed from every opening of the mine and numerous people suffered terrible burn injuries. As the fires continued to burn, rescuers and relatives of the miners were incapable to send help down the mine shafts. One rescue party of 40 men paid the important price for their attempt - they were all killed when the shaft they were descending buckled. Soon, French soldiers were called in to establish order from the escalating pandemonium outside the mine.
Mortuary was established close to the mine as bodies began to be found. It took weeks for the bodies to be recovered and identified. In the end, the casualty toll from this disaster was 1,099 mines killed, with hundreds more suffering serious injuries.

Kingsley ENEM's picture

The disaster happened in Texas, USA on the 16th of April, 1947 while loading ammonium nitrate fertilizer onto a ship (Grandcampe). In the morning, signs of smoulder were seen by the longshoremen from the Hold while waiting to winch the first 100 pound bags of fertilizer from the dock. After a while, a plume was seen rising in the middle of the cargo holds and the ship's hull, apparently about seven or eight layers of sacks downwards.
The fire continued rising and was not capable to be quenched by the crew, the longshoremen were ordered out of the hold. The Grandcampe exploded in the morning hours, pouring tons of molten steel and burning cargo over the town, humans were knocked to the floor and also producing a 15 foot wall of water that eroded over the port.
The emergency rescue and recovery team began in earnest, but the tragedy wasn't over yet. In the evening of that same day, fires were noticed coming from the hold of the High Flyer, a ship which had been sternly damaged in the Grandcampe blast. There was another explosion by the High Flyer ship herself at about at about 1:00am thereby damaging another ship (the Wilson B. Keene), this resulted to rubbles spreading all over the industrial sites. The fires scorched for several days before it was controlled.
The disaster caused the death of 570 humans and injuring about 3,500 people. Most of the corpses were unable to be identified and several residence and port workers were not seen after the incident.
As a result of the disaster, Texas City is better equipped with improved safety standards, emergency systems and good working relationship among industries.


Kingsley ENEM's picture

The Oppau (Ludwigshafen, Germany) facility was built in 1911 over 8 hectares and began production of nitrogenous fertilizers two years later. It comprises of potassium chloride and ammonium nitrate in equal quantities. The raw material ammonia was created using the new Haber-Bosch process that uses atmospheric nitrogen. About eight thousand workers were on the site.
At war times, ammonium salts were manufactured for military use such as constituents for explosives. Although after 1918, ammonium salts continues to be made for civil purposes.
Since 1919, the potassium chloride/ammonium nitrate mixture was progressively substituted by a 50/50 combination of ammonium sulphate and ammonium nitrate called "mischsaltz". This greatly hygroscopic combination had the limitation of clogging together under the pressure of its own weight during storage. The simplest known practice to loosen the "aggregated" product was by firing explosives in holes drilled using a jumper bar in the hardened mass. Until the day of the accident over 20,000 firings were carried out in the "mischsaltz" without any sign of accident being observed.
In the morning of 21st September 19211, the workers were preparing the holes for the firings in the "silo 110", a huge blast occurred in the silo at about 7:32 am, generating 90m X 125m crater. The blast was heard in Munich, 275 km from the plant and triggered panic among the crowds. A dusky green cloud spread across the skies of Ludwigschafen and Mannheim and the whole county was covered in thick smoke. Shortly after the explosion, there were multiple fires on the facility and the air was dense with ammonia fumes.
The consequences of the disaster resulted to 578 deaths, 1,952 injured and 7,500 people were rendered homeless. Among the casualties include passengers from trains arriving on the site for change of shift. Numerous school children on their way to school were injured, boats on the Rhine River were destroyed and sailors injured. Huge glass rubbles on the roads of Heidelberg interrupted traffic in the town.
After the disaster in Oppau, many studies were conducted and a better solution was provided. The studies revealed that the parameters such as the composition of the combination, as well as physical parameters (density, humidity, etc.) increase the capacity of the ammonium sulphonitrate mixture to explode.


Kingsley ENEM's picture

The Aberfan disaster was a ruinous collapse of a colliery spoil tip that happened in the Welsh village of Aberfan on Friday 21 October 1966. About fifty years up to 1966, millions of cubic metres of dug rubbles from the National coal board's Merthyr Vale Colliery were dumped on the side of Mynydd Merthyr, directly overhead the village of Aberfan. Massive piles, or ‘tips', of loose rock and mining spoil had been constructed up over a layer of extremely porous sandstone that contained many underground springs, and several tips had been built up directly over these springs. Though local authorities had raised specific concerns in 1963 about spoil being tipped on the mountain overhead the village primary school, these were basically ignored by the NCB's area management.
Coal waste from the mountain overhead the village swiftly rushed down the mountain, first damaging a cottage and then submerging the school and some houses in the village. A total of 144 people were killed including half the children in the school and five of their teachers. The reason was an underground spring, and two days of heavy rainfall which caused the coal waste on the mountain to loosen. A mass interment was held on the 25th October; over £1 million was collected from public in four months. Some of the money went to the families and towards house repairs, a community hall, and a memorial.
National coal Board refused to admit full charge for the disaster, money from the fund had to contribute towards the removal of the left over tips overlooking the village. This money was not reimbursed until 1997.
The consequence of the tragedy brought about the Mines and Quarries (Tips) Act 1969, which states it is an Act to make further provision in relation to tips associated with Mines and Quarries; to prevent disused tips.

Kingsley ENEM's picture

Benxihu (Honkeiko) Colliery mine located in Benxi, Liaoning, China, was mined in 1905. It began as an iron and coal mining project under Japanese and Chinese control. After a while, the project was hugely controlled by the Japanese. In the early 1930s, Japan invaded the east of China and Liaoning province and forced the Chinese to work the colliery under very poor conditions. The Japanese controllers were known to beat workers with pick handles and may describe the work as slave labour.
In 26th April, 1942, a gas and coal dust blast in the mine killed 1,549 workers, making it the worst disaster in the history of coal mining. The blast sent fires bursting out of the mine shaft entrance. The family of the miners' rushed to the location but were deprived of entry by a barricade of Japanese guards who erected electric fences to keep them out. In an effort to limit the fire underground, the Japanese closed off the ventilation and sealed the pit head. Observers say that the Japanese did not evacuate the pit completely before sealing it; trapping many Chinese workers underground to clog in the smoke. The increased in death toll was as a result of the Japanese actions. It took workers ten days to remove all the corpses and debris from the shaft. Mass burial was conducted for the death. Numerous casualties could not be properly recognized due to the degree of the burns.
The Japanese at first stated the death toll to be just 34 and gave a lower profile of the disaster as a minor event. The control of the mine was not under the Japanese after the World War II in 1945. The workers took control of the mine after the Japanese withdrawal. With the emancipation after the war, the Soviet Union investigated the accident and established that few of the workers died from the gas and coal-dust explosion while most deaths were related to Carbon Monoxide poisoning due to the closing of ventilation after the explosion.


leighmoreton's picture

Due to the new word limit I will not be going into too much detail for my list, I will provide the name of the disaster the date and the reason why.

1.Chernobyl, Ukraine (1986), 31 deaths (1986-2000 350,400 evacuees)
2.Bhopal, India (1984), 5,000 initial deaths, 18,000 after 2 weeks
3.Aberfan, UK (1966), 116 children and 28 adult deaths
4.Piper Alpha, North Sea, 167 deaths
5.China Coal Mining Industry, China (2002 to Present), in 2002- 19 deaths per day, 2011- 6.6 deaths per day[]
6.Gulf War Oil Spill, Kuwait (1991), 11 Million US Barrells spilt
7.BP Deepwater Horizon, Gulf of Mexico (2010), 11 dead, 6.8 Million US Barrells spilt
8.Kleen Energy Refinery, USA (2010), 6 deaths, 225 'willful' safety violations
9.Quetta Mine, Pakistan (2011), 45 deaths
10.Mezhdurechensk, Russia (2010), 91 deaths, 129 injured

There are many other incidents which can also be considered but these are my top ten from a selection.  Please feel free to debate and add your own opinion of my selection.

Leigh Moreton
MSc Renewable Energy

Andrew Strachan's picture

1.Banqiao Dam (1975-China) - 26,000
2.Chernobyl (1986-Ukraine) - 50 directly, 4000+ indirectly
3.Vajont Dam (1959, Italy) - 2000
4.Benxihu Colliery (1942-China) - 1,549
5.Morvi Dam Failure (1979,India) - 1500
6.Courrières mine (1906-France) - 1099
7.Jess Oil Pipeline Explosion (1998-Nigeria) - 1078
8.San-Juanico (1984-Mexico) - 500
9.Senghenydd Colliery (1913-UK) - 439
10.Wankie coal mine (1972-Zimbabwe) - 426

Two conclusions: (i) hydro dams are surprisingly dangerous (ii) The significance of a disaster cannot be merely ranked using fatality statistics alone; historical and geographical context, environmental and social impact as well as impact on future safety legislation are all factors.

Kelvin Osaro's picture

The Chernobyl incident was considered as one of the top ten ranked major accident in the energy sector that occurred on the 26th of April 1986 at the Chernobyl nuclear power plant in Ukraine. The major cause that led to the accident was human error/ operator error and deficiencies in the reactor design and in the operation regulations escalated the accident. Moreover, the physical /technical circumstances that led to the accident were operators lacking the detailed understanding of the technical procedures involved with nuclear reactor and knowingly ignoring regulations to speed up test completion. Hence, the developers of the reactor plant considered this combination of events to be impossible and therefore did not allow for the creation of emergency protection systems capable of preventing the combination of events that led to the disaster, namely the intentional disabling of emergency protection equipment plus the violation of operating procedures. As a result, are among the primary cause of the accident whereby the extremely improbable combination of rule infringement as well as the operational routine allowed by the power station staff [1].

More importantly, with the series of incidents that led to the explosion, fire and nuclear meltdown at Chernobyl has created major harm to the environment. These harms include: the release of large amount of radioactive contamination into the atmosphere, financial loss of about 18 billion rubles that crippled the Soviet economy, causing 57 direct deaths and 4,000 additional cancer deaths in the accident. The consequences of this accident lead to a total transformation of the safety legislation in the nuclear power industry and thereby slowing its expansion for number of years [1].    


Thomas James Smith's picture

In ranking the top ten sever accidents in the energy sector we must first understand the ranking process.  A sever accident is understood to mean an accident that has the ‘potential or actual accidents that represent a significant risk to people, property and the environment ‘[1]. 

Different definitions of ‘significant’ can be found within table 5.2.1 of document ref [1],  But the criteria used by ENSAD to define severe accidents are shown below:

1. at least 5 fatalities or

2. at least 10 injured or

3. at least 200 evacuees or

4. extensive ban on consumption of food or

5. release of hydrocarbons exceeding 10,00 tones or

6. enforced clean-up of land and water over an area of at least 25km2 or

7. economic loss of at least 5 million 1996 US$

Table 9.1.1 to 9.14 ranks the accidents dependant on the above criteria. 1969 - 1996

Worst from each table 

The highest fatalities were from a collision between an oil tanker and a passenger ferry killing 3000 people. Philippines 20.12.1987.

The highest injuries were at an incident in a LPG terminal were a major fire and a series of explosions injured 7231 people were injured. Mexico 19.11.84

The highest number of evacuees was from train derailment that released a fireball into the air, one of the tanks contained chloride gas so as a precaution 220000 people were evacuated. Canada 11.11.79

The highest cost was the Chernobyl nuclear disaster that cost 339,200 x10E6 US$. Ukraine 26.04.86

[1] PSI – Severe Accidents in the Energy Sector First edition

Tilak Suresh Kumar's picture

According to Gary Karasek is a safety
consultant to the oil and gas industry in his blog has listed the top 10 major
accidents over the last century that have had a major influence on our
regulatory regimes and industry standards on risk management

Disaster # 10 – Titanic

Disaster # 9 - Iroquois Theater Fire

Disaster #8 - The Halifax Explosion

Disaster # 7 - Texas City Disaster US

Disaster #6 - Fixborough Chemical Plant

Disaster #5 - Bhopal Disaster

Disaster # 4 - Chernobyl Disaster

Disaster # 3 - Challenger Shuttle Explosion

Disaster #2 - Piper Alpha

Disaster #1 - BP
Macondo/Deepwater Horizon Blowout


Haven carefully examined discussions so far on the top ten energy industry accidents; I identify from the work of Leigh Moreton the industry basis for classification of accidents as severe. The resultant cause and consequence of different accidents have being exhaustively discussed.However, as identified in the essays by Ansabdrahman and Felicia Fleitas, it would be quite difficult to classify severe energy accidents in a rank order of one to ten. It may be easier to achieve if it was possible to convert all the possible consequences into one common unit of asset loss, fatality, loss of reputation, income loss, environmental damage or legal consequences. Although the works of Mark Haley and OGP (Risk assessment data directory, 2010) stimulate a quite acceptable approach to ranking and conversion to cost, they have not thoroughly established a universally agreeable measure of consequence unification. Mark has established that the value for life would vary widely from country to country and could not make a conclusive cost measure for consequence of environmental damage. Some of the consequences like litigation, asset loss and loss of income can be fairly converted to a common cost function, other critical and irreversible consequences like fatality or permanent disability and environmental damage may not be universally convertible to a common consequence function. 


International Association of Oil and Gas Producers. “Risk Assessment Data Directory” Report No. 434 – 17. March 2010.


Haven carefully examined discussions so far on the top ten energy industry accidents; I identify from the work of Leigh Moreton the industry basis for classification of accidents as severe. The resultant cause and consequence of different accidents have being exhaustively discussed.

 However, as identified in the essays by Ansabdrahman and Felicia Fleitas, it would be quite difficult to classify severe energy accidents in a rank order of one to ten. It may be easier to achieve if it was possible to convert all the possible consequences into one common unit of asset loss, fatality, loss of reputation, income loss, environmental damage or legal consequences. Although the works of Mark Haley and OGP (Risk assessment data directory, 2010) stimulate a quite acceptable approach to ranking and conversion to cost, they have not thoroughly established a universally agreeable measure of consequence unification. Mark has established that the value for life would vary widely from country to country and could not make a conclusive cost measure for consequence of environmental damage. Some of the consequences like litigation, asset loss and loss of income can be fairly converted to a common cost function, other critical and irreversible consequences like fatality or permanent disability and environmental damage may not be universally convertible to a common consequence function.  



International Association of Oil and Gas Producers. “Risk Assessment Data Directory” Report No. 434 – 17. March 2010.


I observe from earlier posts that ranking of accidents have been done based on the extent of fatality, financial losses and environmental impact. The consequences, causes and legal consequences have being considered from different research perspectives. Different rankings are outlined due to differences in the consequence considered. Relying on research by contributors to this blog, I have established a statistically recurrent top ten based on a weighting system which I generated.

This is reflected in a chart as shown below:

Basis for the scores was as shown below (using the Bianqiao Dam disaster for instance).

The Bianqiao was ranked No 1 accident by 12 posts, rank 2 by 2 posts and rank 3 by 1 post. 

The rank 1 is given a weight of 10 points.(likewise rank 2 = 9 points, rank 3 = 8 points, rank 4 = 7 points, rank 5 = 6 points, rank 6 = 5 points, rank 7 = 4 points, rank 8= 3points, rank 9= 2 points, rank 10=1point)


No of rank 1 = 12, weight = 12*10 = 120


No. of rank 2 = 2, weight = 2*9 = 18


No. of rank 3= 1, weight = 1*8 = 8


Total Weight = 151

 This weighting was done for all the accidents identified and ranked and the top ten aggregate presented as shown in the figure above.


The consequences of the accidents and causes have being detailed by previous essays and hence is not repeated.


Henry Tan's picture

Interesting statistics!



I have been keeping track of this thread and it appears most people are working
along similar lines to come to their conclusions. This is clear with the same
disasters reoccurring in most lists. 

During some searches myself I came across an accident I don’t believe anyone
has mentioned yet (sorry if I am mistaken).

The incident in question is the 'Centrali, Pennsylvania, Mine fire'. This
mine fire is from my point of view one of the most interesting accidents and
you could say disasters from the past century. This is not due the consequence
of how it began but more down to how it was handled and how it has continually caused

For those of you who don’t know the Centrail Mine fire started on the 
May 27th 1962 and is still burning away to this day. That is over 50 years
straight of burning coal and other minerals.

It started during the annual city clean up before the American holiday of
Memorial day, as they did every year the council lit a controlled fire in the
city dump to burn away all the rubbish. However this year the fire was not extinguished fully
and part of the fire managed to find its way to a coal seam and ignite the
recently abandoned coal mine. 

The usual safety measure for a coal mine at this time was to insert
fire-resistant clay between each layer of coal. This work had however fallen
behind schedule and allowed the fire to continue to the lower layers of the
coal pit creating the subterranean fire. Throughout the next 10-15 years all
attempt to put out the fire failed.

Now I know what you are thinking, so what a fire in an abandoned coal mine
so what and for part you are right, the fire was in a disused coal mine, nobody
as killed and in the beginning there was little disruption to the city. So where
is the severity in this accident?

Well, lets look at what has occurred as result of the fire, 50 years of
burning coal and other minerals. That is an unknown amount of coal, which has
produce vast amount of Carbon dioxide and Carbon Monoxide, as well as sulphur
and other lethal gases. These gases are harmful to people, animals and the environment,
they have been produce continually for 50 years!

The temperature of underground in that area is a staggering around 86ºC, which
makes it almost impossible for substantial plant growth. This temperature and
the conditions underground are constantly adjusting which can lead to random
sinkholes appearing, which are not only deadly to fall in but expel steam and
gases of lethal volumes.

The town its self is a fragment of what it used to be, over the last 20
years the government has spent multimillions on relocation its residents demolishing
building and other work to try and control the fire.

In addition to the environmental issue, the safety issue, the disruption to people’s
lives and livelihood, the condemning of a town and the millions spent to manage
the problem from a business point of view the fire has cause the destruction of
vast amounts of mineable coal, although it was not being mined at the time advancements
in technology no doubt would have lead a company to revisit the site. This has
meant no jobs have been created, no money has been made and no taxes have been
paid, which in the point of view of the government is never good.

 The poor execution of a poorly
located fire has managed to bring down a town, ruin the local environment and
cost the Government Million in costs and potential revenue.

Please note that by no means do I feel the severity of this accident compares
to that of Chernobyl or the Banqlao dam break, however I feel it is a good
example of how a small accident can become a major incident and in its own way
become a very severe accident.


thanks Liam Slaven


eddy itamah's picture

The following severe accidents in the energy sector are ranked in accordance with the numbers of death casualties and the environmental impact of the accident. Also carefully considered were the underlying cause, the factors which led to the escalation of the accident and the physical/technical circumstances surrounding the accident.

1. Banqiao reservoir dam failure in 1975 was considered the worst and most severe accident in the energy sector owing to the numbers of casualties. According to report, the Banqiao dam failure in china in 1975 killed an estimated 230, 000 people, and rending 11million people homeless. The Banqiao dam failure was reported to have failed as a result of poor engineering design, and neglecting to consider the hydrology data.

2. San Juanico disaster in november 19 1984, were an industrial disaster cause a massive series of explosions at a liquid petroleum gas tank farm in san juanico, mexico. The explosion destroyed the facility and devastaed the local town of san juanico lxhuatepec, killing 500 - 600 people, while 5000 - 7000 people suffer from severe burns. This san juanico disaster was one of the deadliest industrial disaster in the world history.

3. Piper Alpha which is regarded as the worst offshore oil disaster in terms of lost of lives and industry impact is considered the third severe accident in the energy sector. In july1988, there was an explosion of oil and gas resulting in fire that killed 167men onboard the platform, and a total insured loss of US$3.4billion.

4. Ocean Ranger disaster in february 15 1984 is ranked the fourth on this list. Ocean Ranger, a semi submersible mobile offshore drilling unit sank in canadian waters on the 15th february 1984 which led to the death of all 84 workers onboard the semi - submersible unit. Report shows that the cause of the disaster was as a result of the following

- A broken portlight caused by a large wave

- The broken portlight allowed the ingress of sea water into the ballast control room, and the non availability of detailed instructions and personnel trained in the use of the ballast control panel.

5. Chernobyl disaster in April 26 1986 is ranked the fifth severe accidents in the energy industry. A situation in which one reactor in the chernobyl nuclear plant in Ukraine went out of control during a test resulting in a nuclear meltdown. The ensuing steam explosion and fire killed up to 50 people with estimates that there may be between 4,000 and several hundred thousand additional cancer deaths over time.

6. Romeoville llinois in july 23 1984 in which union oil refinery exploded killing 19 people.

7. Texas city refinery explosion in march 2005. An explosion which occurred at BP refinery in Texas city. This explosion led to the death of 15 workers and 100 workers were severely injured. The remote cause of this accident was attributed to the failing of several level indicators, leading to overfilling of a knock out drum and lighting hydrocarbon concentrated at ground level throughout the area.

8. Deepwater Horizon oil spill in the Gulf of Mexico in April 20 2010 killing 11 oil platform workers in an explosion and fire that resulted in a massive oil spill in the Gulf of Mexico.

9. Exxon valdez oil spill in march 24 1989 in which an oil tanker bound for long beach, california hits prince william sound's Bligh Reef dumping an estimated minimum 10.8million US gallons of crude oil into the sea. This accident is considered to be one of the most devastating human - caused environmental disaster ever to occur in history.

10.   Fukushima Nuclear accidents in japan in march 2011 is considered to be the tenth severe industrial accidents in the energy sector. This accident is regarded as the largest disaster since the chernobyl disaster although there were no direct direct deaths, but a few of the plants workers were severely injured or killed by the disaster resulting from the earthquake.



Connie Shellcock's picture

I would just like to add that a lot of the time
attention is brought to a disaster or activity that went wrong and then
analysed to see what we can learn from it. But why is attention not brought to
activities that went well? If a task is carried out correctly with no mistakes
made then most of the time nothing is said. Surely it is just as important to
look at what went well and what went wrong. But this doesn’t seem to be the
case. It seems as if only operations that have a poor outcome or had been
performed badly are noteworthy. It is my opinion that this should change. We
can learn just as much from a successful operation as we can an unsuccessful

Omololu Oyebola's picture

The energy sector has witnessed several disasters in the past; the following below are arranged by date and their severity depends on the angle which you perceive at them

The Centralia, Pennsylvania coal mine fire (May 1962)

The Banqiao Dam (August, 1975)

Chernobyl disaster (April 26, 1986)

Norco, Louisiana (May 5, 1988)

Piper Alpha disaster (July 6, 1988)

Exxon Valdez oil spill (March 24, 1989)

Texas City Refinery explosion (March 23, 2005)

Connecticut power plant explosion (February 7, 2010)

Deep-water Horizon oil spill in the Gulf of Mexico (April 20, 2010)

Fukushima I nuclear accidents in Japan (March 2011)

As future engineers, let is ensure we get our work right to avoid the occurrence of such ghastly incidents by carrying out proper designs, proper material selection process, and post installation integrity checks to ensure facilities are properly maintained. 

Kevin K. Waweru's picture

All manner of categories have been explored in ranking the top ten energy sector accidents, hence I am not going to try and invent a new categorisation.

However, I have ranked the top ten accidents based on the recorded approximate number of fatalities on record for the simple reason that a life lost cannot be replaced. 


 No. Of Fatalities

Banqiao [1] 
Dam failure 

 Morvi dam failure [2]
Dam failure 

 Bhopall [3]
Gas leak 

 Vajont [4]
Dam failure 

 Benxihu (Honkeiko) [5]
Coal mine explosion 

 Jesse, Niger Delta [6]
Oil pipeline explosion 

Piper Alpha [7] 
Offshore production platform explosion 

 Aberfan [8]
Colliery mining heap collapse 

 Chernobyl [9]
 Nuclear plant explosion

 Macondo, Deep Water Horizon [10]
Offshore drilling rig explosion    













I contend that my basis for severity ranking and number and fatalities are open to challenge.

Kevin K. Waweru

MSc Oil and Gas Engineering

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