Tag Archives: fire

Root Cause Analysis - Incident Investigation

Deadly Sawmill Explosion

By ThinkReliability Staff

An explosion and subsequent fire at a sawmill in British Columbia has killed two workers and injured two dozen more.  Although the cause of the explosion is not known, there have been five explosions linked to wood dust in British Columbia since 2009.

A dust explosion results from the presence of combustible dust, such as that created by the sawmilling process.  In order for an explosion to occur, the dust must be dispersed into the air but confined by a structure in the presence of oxygen and a spark.  (Learn more about dust explosions.) 

To view all the causes that contributed to this tragic explosion, we can examine the incident in a Cause Map, or visual root cause analysis.  We begin with the impacts to the goals. The employee deaths and injuries are an impact to the safety goal.  This is the primary focus of any issue that results in human death or injury.  In addition, the environmental goal was impacted as the smoke migrated to the nearby town.  The production goal was impacted due to the shutdown of the facility.  The property goal was impacted due to destruction of the sawmill, log processing facility, and sorting facility.  Lastly, the investigation and cleanup will impact labor goals.

Once we have determined the impacts to the goals, we can ask why questions to determine the cause-and-effect relationships that led to the incident.  In this case, the injuries were due to the fire.  The fire may have been caused by a dust explosion (explosion due to natural gas leak has been ruled out).  In order for a dust explosion to occur, five factors are necessary: 1) presence of combustible dust, 2) oxygen, 3) dust is dispersed into the air, 4) dust particles are confined, and 5) the mixture is ignited.

In this case, the ignition source is not known and, due to the damage at the facility, may never be conclusively determined.  Similarly, the cause that resulted in the dust being dispersed may also not be known.  The oxygen must be present for worker safety and the dust is confined because it is held within a closed structure.  The dust is present because it is created during sawmilling operations.  What makes a dust combustible depends on the properties of the dust.  This mill was processing pine beetle wood, or wood that was ravaged by beetles.  This makes the wood drier, which results in a drier, finer, more combustible dust.  Thorough cleaning of any facility that creates potentially combustible dust is a necessity – inadequate cleaning (including dust that may gather on hard-to-access surfaces, such as the ceiling) increases the possibility of an explosion.  The union believes that cleaning has been reduced as a result of the economy.

Local government has begun inspections of saw mills but are asking plants to examine potential dust and ignition sources. Reducing dust and ignition sources are the most effective way to reduce risk of dust explosions.  Other solutions being considered include adding water to the air to increase humidity and increased ventilation, which can reduce the confinement of the dust and increase cleanliness.

To view the Outline and Cause Map, please click “Download PDF” above.

 

Root Cause Analysis - Incident Investigation

Cruise Ship Loses Power

By Kim Smiley

Part of the excitement involved in passenger cruises is access to remote areas of the world.  However, when a ship runs in to trouble, that remoteness can result in extremely difficult conditions.  This was the case on the Costa Allegra, which suffered an engine room fire in the Indian Ocean.

Passengers aboard the Costa Allegra experienced sub-standard conditions when the ship lost power and propulsion due to an engine room fire.  During the three days while the ship was being towed to land, there was no air conditioning, lighting, or running water.  Food and drinking water were provided by helicopter.

We can examine the causes and effects of this issue in a Cause Map, or visual root cause analysis.  With the Cause Mapping process, we begin by examining the impact to the goals.  Namely, when the incident occurred, which of the organization’s goals were not met?  In this case, although there appeared to be no injuries resulting from the fire itself (although some passengers may have become ill during the resulting conditions) there was the potential for severe injury resulting from the fire and then the lack of power that resulted.   Additionally, the customer service goal was impacted by the lack of running water, air conditioning, and lighting.  The schedule goal was impacted because the ship needed to be towed for 3 days.  The property goal was impacted due to the damage to the ship from the fire, and the labor goal was impacted due to the need for the ship’s crew to stand guard against pirate attack.

Once we’ve determined the goals that were impacted, we can use them as a basis for our map, and ask “Why” questions to add more detail.   Here, an engine room fire on the ship resulted in the loss of ship power, causing the loss of air conditioning, lighting and running water, and the loss of ability for the ship to propel itself, necessitating a tow.  The length of the tow is also affected by the type of ship doing the towing.  In this case, the first ship to arrive to the aid of the Costa Allegra was a fishing vessel.   Although tugboats later arrived, the Costa Allegra requested that the fishing vessel continue the tow, although it is believed that the tugboats would have been able to speed up the tow, possibly resulting in the ship arriving as much as 12 hours earlier.  The cruise ship company has stated that the tow was not changed in consideration of the consistency of the voyage for the passengers but there are also potentially financial considerations.  Assistance to people at sea is not paid, but assistance to ships is.  Thus, the fishing vessel actually entered into a contract with the cruise ship for the tow.

Part of the reason that a fishing vessel was the first to arrive is that there is little maritime traffic in the area.  This is due to the remoteness of the area in which the cruise ship was traveling, as well as the risk of piracy.  This, of course, led to a constant armed guard on the disabled ship to protect from potential pirate attack.

The location to which the ship was towed also impacts the length of the tow.  It was determined that smaller ports closer to the location of the disabled Costa Allegra could not accommodate the large number of passengers on the ship, so the ship was towed to an island of Seychelles.

The cause of the fire itself is still under investigation, although it is believed that an electrical fault is a likely cause and that arson is not likely.  As more information becomes available, we can add that information to the Cause Map as well.

To view the Outline and Cause Map, please click “Download PDF” above.

Root Cause Analysis - Incident Investigation

Honduran Prison Fire

By ThinkReliability Staff

How do you know when your solutions haven’t been effective?  When the same problem keeps happening.  Another prison fire claimed 360 lives in Honduras.  This is the third fatal prison fire in nine years, resulting from  chronic overcrowding and understaffing of Honduran jails.

Just more than 3 years since over 100 prisoners were killed in a prison fire  in San Pedro Sula (see previous blog), 360 prisoners (so far) have died as a result of a fire in Comayagua Prison.  (A fire in 2003 claimed the lives of 68 prisoners.)  An open flame has been determined to be the cause of the fire but contributing to the deaths is that the prisoners were unable to get out.

With any incident resulting in deaths of this magnitude, we can analyze the causes of the incident using a visual root cause analysis, or Cause Map.  We begin with the impacts to the goals.  In this case, the prisoner deaths were an impact to the safety goal.  In addition, prison overcrowding can be considered an impact to the production goal, and a delay in rescue can be considered an impact to the customer service.  Any damage resulting to the prison itself as  a result of the fire is an impact to the property goal.  Once we’ve determined the goals that were impacted, we can begin the analysis by asking “why” questions.

An investigation determined that an open flame (such as a cigarette or candle) and not arson, as was suggested prior to the investigation, caused the fire.  However, severe overcrowding (more than 800 prisoners were in a jail with a capacity of 500) and a delay in the rescue of the prisoners contributed to the massive death toll.

Honduras has a chronic overcrowding problem.  Honduras has a high rate of homicides and a high number of gang members.  Gang members receive strict sentences and, in many cases, are jailed prior to conviction.  However, an increased number of  inmates has not led to an increased number of guards.  On the night of the fire, there were 6 guards on duty.  Guards who were in the towers were not allowed to leave their posts to help with the fire-fighting and rescue efforts.  The guard who had the only set of keys fled prior to unlocking the doors.  (The guards are facing disciplinary actions.)  Firefighters were not allowed to enter the jail for 30 minutes after the fire call as the guards believed they were experiencing a riot or breakout.  An inmate who was not in his cell at the time of the fire was able to free many prisoners.

This incident has added more fuel to the international outcry over the state of Honduras prisons.   However, not much appears to have been done to improve conditions since the previous fires in 2003 and 2009, so it’s unclear if anything will change as a result of this fire.   It is certainly apparent that the safety of prisoners cannot be maintained with the current overcrowding and number of guards.  Additionally, procedures in the case of a fire certainly need to be improved to ensure that prisoners can be evacuated safely and securely.

To view the Outline and Cause Map, please click “Download PDF” above.

Root Cause Analysis - Incident Investigation

Prison Fire Kills 103 in 2009

By Staff

On February 9, 2009, a fire and explosion in a seriously overcrowded prison in Honduras resulted in 103 deaths and 25 injuries.  The fire was started from a short circuit from a overheated refrigerator motor, used to store soft drinks for the inmates.  The cell block – which has a capacity of 800 – contained 1960 inmates, their clothing, and their bedding materials.  This provided plenty of fuel for the fire.

We can look at the causes that led to the prisoner deaths in a Cause Map, or visual root cause analysis.  We begin with the impacts to the goals.  The deaths and injuries of prisoners are an impact to the safety goal.  The environmental goal was impacted by the severe prison fire and explosion.  The customer service goal (considering the general population as the “customer” of a government-run prison) was unaffected, as there were no prisoner escapes.  Finally, the property goal was impacted due to damage to the prison.

We can continue the Cause Map by asking “why” questions.  The impacts to the goals were due to a severe prison fire and explosion.  In addition to the fire, the injuries to the prisoners was caused by the prisoners being unable to escape.  Part of the reason the prisoners were unable to escape is because they are in prison, and so precautions against escape are part of the deal.  However, egress from a building that is on fire to a safe location should be part of the procedures of any prison.  In this case, the procedures obviously didn’t work considering the high amount of deaths and injuries (of a total of 186 prisoners in this cell block).  The egress was likely made more   difficult due to severe prison overcrowding.  The prison has a capacity of 800 and contained 1,960 prisoners.  The increase in the prison population is at least partially due to a legislation passed the previous August which mandated a minimum 12-year prison term for gang members.  There are estimated to be more than 100,000 gang members in Honduras.

The heat for the fire was provided by an overheating refrigerator motor.  The fuel was provided by large amounts of clothing and bedding materials – more than usual, due to the prison overcrowding.

Once the causes for the impacted goals have been determined, solutions can be brainstormed.  In this case, prisoner advocates have been long calling for alternatives to jail sentences for gang members.  This would, of course, reduce the prison population.  Another option to reduce prison overcrowding would be to build more prisons.  To reduce the risk of fire, motorized equipment should be kept away from flammable objects, like clothing and bedding.  Last but not least, any facility has to have an effective egress plan in the case of fire or other emergencies.  These procedures are especially important in the case of a prison, where the potential of prisoner escape has to be considered as well as prisoner safety.

To view the root cause analysis investigation, please click “Download PDF” above.  Or click here to read more.

Root Cause Analysis - Incident Investigation

Great Seattle Fire

By ThinkReliability Staff

On June 6, 1889, a cabinet-maker was heating glue over a gasoline fire.  At about 2:30 p.m., some of the glue boiled over and thus began the greatest fire in Seattle’s history.  We can look at the causes behind this fire in a visual root cause analysis, or Cause Map.  A thorough root cause analysis built as a Cause Map can capture all of the causes in a simple, intuitive format that fits on one page.

First we begin with the impacts to the goals.  There was one confirmed death resulting from the fire, and other fatalities resulting from the cleanup.  These are impacts to the safety goal.  The damage to the surrounding areas can be considered an impact to the environmental goal.  The fire-fighting efforts were insufficient; this can be considered an impact to the customer service goal.  Loss of water and electrical services is an impact to the production goal, the destruction of at least 25 city blocks is an impact to the property goal, and the rebuilding efforts are an impact to the labor goal.

Beginning with these impacted goals, we can lay out the causes of the fire.  The fire did so much damage because of the large area it covered.  It was able to spread over downtown Seattle because it continued to have the three elements required for fire – heat, fuel, and oxygen.  The heat was provided by the initial fire, oxygen by the atmosphere, and plenty of fuel with dry timber buildings.  The weather had been usually dry for the Pacific Northwest, and most of the downtown area had been built with cheap, abundant wood.

Additionally, fire fighters were unable to successfully douse the flames.  The all-volunteer fire department (most of whom reportedly quit after this fire) had insufficient water – hydrants were only placed at every other block, and the water pressure was unable to sustain multiple fire-fighting hoses.  Additionally, some of the water piping was also made of wood, and burned in the fire.  Firefighters attempted to pump water from the nearby bay, but their hoses were not long enough.

Before spreading across the city, the fire spread across the building where it began.  The fire began when glue being heated on a gasoline fire boiled over and lit.  The fire then began to burn the wood chips and turpentine spilled on the floor.  When the worker attempted to spray water at the fire, it only succeeded in spreading the lit turpentine, and thus the fire.  When firefighters arrived, the smoke was so thick that they were unable to find the source of the fire, and so it continued to burn.

The city of Seattle instituted many improvements as a result of this fire.  Wood burnings were banned in the district, and wood pipes were replaced.  A professional fire department was formed, and the city took over the distribution of water.  Possibly because of the vast improvements being made (and maybe because of the reported death of 1 million rats in the fire), the population of Seattle more than doubled in the year after the fire.

View the Cause Map by clicking on “Download PDF” above

Root Cause Analysis - Incident Investigation

Residential Natural Gas Explosion

By ThinkReliability Staff

The town of Allentown, Pennsylvania suffered severe physical and emotional damage on February 9, 2011, when 5 people were killed and 8 homes were completely destroyed.  The deaths and destruction were believed to be caused by a natural gas explosion, fueled by a 12″ gas main break.  In addition to the impacts to the safety and property goals, the natural gas leak, extended fire, and time/labor by 53 responders also impacted goals.

We can analyze the causes of these impacts to the goals with a visual root cause analysis.  Beginning with the impacts to the goals, we ask why questions to determine the causes that contributed to the incidents.  In this case, there was a delay in putting out the fire because the fire had a heat source from the explosion, a constant oxygen source (the environment) and a steady supply of fuel, as the natural gas continued to leak.  There was no shut-off valve to quickly stop the flow of gas.  It took the utility company 5 hours to finally turn off the gas.  It took 12 more  hours before the fire was completely put out.

The fuel for the explosion and the fire is believed (according to the utility company) to have come from a break discovered in the 12″ gas main.  A 4′ section of pipe, removed on February 14th, is being sent for a forensic analysis to aid in determining what may have contributed to the crack.  It’s possible there was prior damage – such as that from weather or prior excavations.  Most of the pipe in the area was installed in the 1950s, although some is believed to be from the 1920s.  Budget shortfalls have delayed replacing, or even inspecting the lines in the area, and officials have warned that continuing financial issues may continue to delay inspections and improvements,  causing concern with many residents, who suffered a similar natural gas pipeline explosion in 1994.

Because implementation of potential solutions to improve the state of the utility lines in the area may be limited by available funding, it’s unclear what will be done to attempt to reduce the risk of a similar incident in the future.   However, the unacceptability of resident casualties should stir some action so that this doesn’t happen again.

Root Cause Analysis - Incident Investigation

Chinatown Fire NYC

By ThinkReliability Staff

On April 11, 2010, a fire broke out in a store on the first level of an apartment building on the 200 block of Grand Street in Chinatown, New York City. The fire would eventually reach 7 alarms, requiring 250 firefighters to fight. Once firefighters were able to enter the building the next day, they found one body.  33 people, including 29 firefighters, were injured and approximately 200 were left homeless, as the blaze left three buildings needing to be demolished and at least two more severely damaged.

For years the buildings affected (which were more than a century old) had been neglected, including violations for missing smoke detectors and a boiler which released smoke into the buildings.  At this point it’s unclear how these violations may have contributed to the fire and its aftermath.  At the time of the fire, the buildings were for sale for over $9 million, although no offers had been made.    There were many goals impacted by the fire, but the loss of human life and number of injuries are the focus for our investigation.

The injuries (many of which were smoke inhalation) were caused by a seven-alarm fire.  The fire was able to reach seven alarms because the fire was able to quickly spread through the six-story building.  In order for a fire to start heat, fuel and oxygen are required.  There’s no shortage of fuel and oxygen in an apartment building, due to necessities for people to live there.  The heat (or ignition source) may have been provided by exposed wiring that many residents have complained of, or the boiler previously cited for neglect.  Or, it may have been something else altogether.  (However, arson is not suspected at this point.)

The fire was able to spread so quickly due to a large number of voids and shafts in the building – a function of its  age.  Another cause that may have contributed to the death was a potential lack of warning of the fire due to the missing smoke detectors for which the building had also been previously cited.

Throughout an investigation there may be additional tools that help to clarify the incident.  Here we use a timeline to show the sequence of events.  A timeline is especially useful for complex events such as this.

A thorough root cause analysis built as a Cause Map can capture all of the causes in a simple, intuitive format that fits on one page.  In fact, the outline, Cause Map and timeline for this event easily fit on one page.  (View them by clicking “Download PDF” above.)   Even more detail can be added to this Cause Map as more information is released about the incident. As with any investigation the level of detail in the analysis is based on the impact of the incident on the organization’s overall goals.

Root Cause Analysis - Incident Investigation

Today in History: Fire on the USS Enterprise

By ThinkReliability Staff

On January 13, 1969, 31 years ago, fires and explosions broke out on the USS Enterprise (CVN-65). The crewmembers spent three hours fighting the fire. When the smoke cleared, 27 crewmembers were killed and 314 were injured. Additionally, 15 aircraft were destroyed and the carrier was severely damaged.

We can address the impacts to the U.S. Navy’s goals in a problem outline as the first step of the Cause Mapping process. There was an impact to the safety goal because crewmembers were killed and injured. There was an impact to the property goal because of the 15 planes that were damaged, and the repairs that were required to the ship. (This is also an impact to the labor goal, because of the labor required for the repairs.) Additionally, the ship’s deployment was delayed, which is an impact to both the customer service and production/schedule goals.

After we’ve completed the outline, we build our Cause Map beginning with the goals that were impacted. The goals were impacted by a series of explosions and fires across the ship. These explosions and fires were fueled by jet fuel and bombs that were found on the planes on the flight deck of the carrier. The initiating event was the explosion of a Mk-32 Zuni rocket, which exploded when it overheated due to being put in the exhaust path of an aircraft starting unit.

After the incident, the Navy performed an investigation to review the causes of the incident, and made changes to improve safety. Repairs to the Enterprise were completed, and the ship is now the oldest active serving ship in the U.S. Navy.

A thorough root cause analysis built as a Cause Map can capture all of the causes in a simple, intuitive format that fits on one page. To view the downloadable PDF, click “Download PDF” above.