Tag Archives: fatalities

Root Cause Analysis - Incident Investigation

10,000 Pound Buoy Falls on Workers

By Kim Smiley

On December 10, 2014, a buoy that weighs close to 10,000 pounds fell onto workers at an inactive ship maintenance facility in Pearl Harbor. Two workers were killed and two others sustained injuries. While an object this large is an extreme example of the dangers of dropped objects, worker injuries and deaths from falling objects of all sizes is a significant safety concern. A US census report of fatal occupation injuries states that 245 workers were killed after being struck by falling objects in 2013 alone.

The case of the dropped buoy can be built into a Cause Map, a visual root cause analysis, to better understand what happened. Understanding the details of an accident is necessary to ensure that a wide range of solutions is considered and that any solutions implemented will be effective at preventing future incidents.

The investigation into the falling buoy is still underway so some information is not yet available, but it can easily be incorporated into the Cause Map once it is known. Any causes that need more information or evidence can be noted with a question mark to show that there is still an open question.

Exactly what caused the buoy to drop hasn’t been released yet, but it is known that the safety lines attached to the buoy failed. Both of these issues need to be investigated to ensure that solutions can be implemented to prevent further tragedies.

Additionally, there are open questions about why people were working under the path of the lift. The workers were wearing hard hats, but this is obviously inadequate protection against a 10,000 buoy. The contractors were working to strengthen mooring lines at the time of the accident, but no one should be where they could be crushed if such a large object was dropped, as it was in this case. As stated by Jeff Romeo, the Occupational Safety and Health Administration (OSHA) Honolulu area director, “We’re still looking at the facts to try to determine the exact locations of where these employees were located. If in fact, they were working directly underneath the load, then that would be an alarming situation.”

The OSHA investigation is currently underway and is expected to take four to six months. Additionally, the Navy is launching a Safety Investigation Board to review the accident with findings expected to be released by February. Once the investigation is complete, work processes will need to be reviewed to see what changes need to be made to prevent any future injuries from falling objects.

To view an initial Cause Map of this incident, click on “Download PDF” above.

Root Cause Analysis - Incident Investigation

Chemical Release Kills Four Workers at Texas Pesticide Plant

By ThinkReliability Staff

In the early morning hours of November 15, 2014, a release of methyl mercaptan resulted in the deaths of four employees at a plant in Texas that manufactures pesticides. The investigation into the source of the leak is still ongoing, though persistent maintenance problems had been reported in the plant, which was shut down five days prior to the incident.

Even though the investigation has not been completed, there are some lessons learned that can be applied to this facility, and other facilities that handle chemicals, immediately.

Even “safer” chemicals are dangerous when not treated properly. The chemical released – methyl mercaptan – is stored as a safer alternative to methyl isocyanate (which was the chemical released in the Bhopal disaster). Although it’s “safer” than its alternatives, it is still lethal at concentrations above 150 parts per million. The company has stated that 23,000 pounds were released – in a room where complaints were made about insufficient ventilation. The workers were unable to escape – likely because they were quickly incapacitated by the levels of methyl mercaptan and did not have the necessary equipment to get out. (Only two air masks and oxygen tanks were found in the area where the employees were.)

A fast response is necessary for employee safety. Records show that 911 was not called for an hour after the employees were trapped. (One of the victims called his wife an hour prior to indicate there was an issue and he was attempting rescue.) The emergency industrial response group, which is trained to provide response in these sort of situations, was never called by the plant. Medical personnel could not access the employees because they were not trained in protective gear. Firefighters who responded did not have enough air to travel through the entire facility and did not have enough information on the layout to know where to go. It’s unclear whether a quicker response could have saved lives.

Providing timely, accurate information is necessary for public safety. The best way to determine the impact on the public is to measure the concentration of released chemicals at the fenceline (known as fenceline monitoring). Air monitoring was not performed for more than four hours after the release. Companies are not required to provide fenceline monitoring, although an Environmental Protection Agency (EPA) rule requiring monitoring systems for refineries is under review. (This rule would not have impacted this plant as it produced pesticides.) Until that monitoring, the only information available to the public was information provided by the company (which did not release until days later the amount of chemical released.) In Texas, companies are required to disclose the presence of chemicals, but not the amount. A reverse 911 system was used to inform residents that an odor would be present, but did not discuss the risks.

What can you do? Ensure that all chemicals at your facility are known and stored carefully. Develop a response plan that ensures that your employees can get out safely, that responders can get in safely (and are apprised of risks they may face), and that the public has the necessary information to keep them safe. Make sure these plans are trained on and posted readily. Depending on the risk of public impact from your business, involving emergency responders and the public in your drills may be desired.

To see a high level Cause Map of this incident, click on “Download PDF” above.

Root Cause Analysis - Incident Investigation

Safety Concerns Raised by 5 Railroad Accidents in 11 Months

By ThinkReliability Staff

The National Transportation Safety Board investigates major railroad accidents in the United States. It was not only the severity (6 deaths and 126 injuries) but the frequency (5 accidents over 11 months) of recent accidents on a railroad that led to an “in-depth special investigation“. Part of the purpose of the special investigation was to “examine the common elements that were found in each”.

When an organization sees a recurring issue – in this case, multiple accidents requiring investigation from the same railroad, there may be value in not only investigating the incidents separately but also in a common analysis. A root cause analysis that addresses more than one incident is known as a Cumulative Cause Map, and it captures visually much of the same information in a Failure Modes and Effects Analysis, or FMEA.

The information from the individual investigations of each of these accidents can be combined into one analysis, including an outline addressing the problems and impacts to the goals from the incidents as a whole. In this case, the problems addressed include issues on the Metro-North railroad in New York and Connecticut from May 2013 to March 2014. The five incidents during that time period resulted in 4 customer deaths and 126 injuries, 2 employee deaths, and over $23.8 million in property damage.

The analysis of the individual accidents can be combined in a Cumulative Cause Map to intuitively show the cause-and-effect relationships. The customer deaths and injuries, and the property damage, resulted from train derailments and a collision. The train collision resulted from a derailment. In two of the cases, the derailment was due to track damage that had either been missed on inspection or had maintenance deferred. In the third derailment (discussed in a previous blog), the train took a curve at an excessive rate of speed due to fatigue of the engineer. Inadequate track inspections and maintenance, and deferred maintenance were highlighted as recurring safety issues to the railroad.

Both of the employee fatalities resulted from workers being struck by a train while performing track maintenance. In one case, the worker was outside the designated protected area due to an inadequate job safety briefing. In the other, a student removed the block while working unsupervised, allowing a train to travel into the protected area. The NTSB also identified inadequate safety oversight and roadway worker protection procedures as areas needing improvement. While the NTSB already released recommendations with each of the individual investigations, it plans to issue more based on the cumulative investigation addressing all five incidents. View an overview of all 5 incidents by clicking “Download PDF” above.

Root Cause Analysis - Incident Investigation

Years of Uncontrolled Leakage Lead to Fatal Mall Collapse

By ThinkReliability Staff

The problems that led to the collapse of a shopping mall’s parking structure were present over its thirty-plus year history says the Report of the Elliot Lake Commission of Inquiry. Multiple opportunities to fix the problem were missed, culminating in the deaths of two on June 23, 2012. Says the report, “Although it was rust that defeated the structure of the Algo Mall, the real story behind the collapse is one of human, not material failure.”

Yes, corrosion of a connection supporting the parking garage decreased its strength to 13% of its original capacity, meaning that on that fateful day, one car driving over it resulted in its fatal collapse. But the more important story is that of how the corrosion was allowed to increase unchecked, due to leakage that had been noted since the opening of the mall.

Multiple causes were discovered resulting in the fatal collapse. The report that addresses them and suggests improvement is more than 1,000 pages long. Though the detail in the report is outstanding, an overview of the information from the report can be diagrammed in a Cause Map, or visual root cause analysis, allowing a one-page overview that clearly shows the cause-and-effect relationships.

It’s important to begin with the impact to the goals. Doing so gives a starting point – and focus – to the cause-and-effect questioning. In this case, the safety goal was impacted due to the 2 fatalities and 19 injuries caused by the collapse. The mall experienced severe damage, and the rescue and response efforts were comprehensive and time-consuming. Additionally, an engineer was criminally charged due to negligence from issues with the mall’s structural integrity.

The fatalities, property damage, and rescue efforts all resulted from the catastrophic collapse of the mall’s rooftop parking structure. The collapse was caused by the sudden failure of a connector. Material failure results from stress on an object overcoming the strength of the object. In this case the stress on the object was a single vehicle driving over the connection in question (evidenced by a video of the collapse). The strength of the connection had been significantly reduced due to corrosion, caused by the continuous ingress of water and chlorides on the unprotected beam.

The leakage was found to stem from a faulty initial design of the waterproofing system from construction of the mall in 1979. Specifically, the architect’s suggestions regarding waterproofing were ignored due to cost and land availability concerns, and the waterproofing system was installed during suboptimal weather because of construction delays. After construction, the architect signed off on the design without inspecting the site, beginning the first in a long list of failings that would eventually cost two women their lives.

Over the years, there were multiple warnings (not the least the need to use buckets to collect leaking water on a fairly constant basis) that were never resolved. According to the report, the problem was never fully addressed with maintenance and repairs but rather pushed off with cheap, ineffective repairs or by selling the structure (as happened twice in its history). For the most part, the local government did not investigate complaints or enforce building standards, apparently unwilling to interfere with the operation of a large source of local revenue and employment

When the local government finally did get involved and issued an Order to Remedy in 2009, the building owner appeared to provide deliberately false information that suggested that repairs were underway, leading to a rescinding of the order later that year. After an anonymous complaint in late 2011, an engineer with a suspended license performed a visual-only inspection which had to be signed off by a licensed engineer. After it was signed, the engineer testified that he had changed the contents of the report at the request of the owner, leading to the criminal charges against him for negligence.

Although plenty of failings were discussed in the report, it states very clearly, “This Commission’s role is not to castigate or chastise; its only purpose in finding fault, if it must, is to seek to prevent recurrence. Criticism of prevailing practices serves only to suggest their improvement or, if necessary, elimination.” In the report, the Commission discusses multiple suggestions for improvement – specifically clarifying, enforcing, and providing public information regarding building standards. Hopefully, the lessons learned from this tragic accident will allow for implementation of these solutions to ensure that thirty years of negligence isn’t allowed to cause a fatal building collapse again.

Root Cause Analysis - Incident Investigation

Two Firefighters Killed by Rogue Welding

By ThinkReliability  Staff

On March 26, 2014, two firefighters were killed when trapped in a basement by a quickly spreading, very dangerous fire in Boston, Massachusetts. These firefighters appear to have been the first to succumb to injuries directly caused by fire while on the job in 2014. The company that was found responsible for starting the fire has been fined by OSHA for failure to follow safety procedures. Says Brenda Gordon, Occupational Safety and Health Administration (OSHA)’s director for Boston and southeastern Massachusetts, “This company’s failure to implement these required, common-sense safeguards put its own employees at risk and resulted in a needless, tragic fire.”

Every incident that results in a fatality should be carefully investigated. Investigations are used not only for liability and regulatory reasons, but also to develop solutions to reduce the risk of similar fatalities happening in the future. Investigating an incident such as this in a Cause Map, or visual root cause analysis, allows for better solutions by determining all the cause-and-effect relationships that led to the issue.

First it’s important to define how goals were impacted in order to define the scope of the problem. In this case, two firefighters were killed, which impacts the safety goal. In addition, the spread of the fire, damage of nearby buildings and associated civil lawsuits are also impacts to the goals. The OSHA fine of $58,000 for 10 violations of workplace safety regulations is an impact to the regulatory goal. The response to the fire, as well as the multiple investigations, are impacts to the labor/time goal.

Beginning with an impacted goal and asking “Why” questions develops cause-and-effect relationships that explain how the incident occurred. In this case, the firefighters perished when they were trapped by fire. The firefighters were in the basement of a residential building to rescue occupants from a fire, and the fire was so hot and dangerous that the firefighters could not exit, and other firefighters were unable to come to their rescue. Extremely windy conditions spread the fire caused by a welding spark that struck a nearby wood shed.   OSHA investigators note that the company performing the welding did not follow safety precautions (including having a fire watcher and moving welding away from flammable objects) that would have reduced the risk for fire. They cited the lack of an effective fire prevention/ protection program and a lack of training in workplace and fire safety. View the Cause Map by clicking “Download PDF” above.

Ideally the fine levied by OSHA will encourage the company involved to increase its methods of fire protection, not only to protect its own workers, but also to protect the public. In addition, the Boston Fire Department is conducting an internal review to improve firefighter safety. Says Steve MacDonald, spokesman, “What they’re doing is looking at policies and procedures. They’re reviewing everything, reviewing weather, radio communications, anything and everything having to do with the fire.”

On July 5th, another firefighter died after being trapped in a building while looking for occupants during a fire in Brooklyn, New York. On July 9th, a firefighter in Houston, Texas was killed of smoke inhalation inside a burning building. A firefighter died in a building collapse due to fire in New Carlisle, Indiana on August 5, 2014, making a total of 5 firefighters who have died as a direct result of smoke/fire injuries while on the call of duty so far in 2014. In 2013, a total of 30 firefighters were killed on the job, most as the result of the Yarnell Hill fire in Arizona.

Root Cause Analysis - Incident Investigation

Freight Trains Collide Head-On in Arkansas

By Kim Smiley

On August 17, 2014, two freight trains collided head-on in Arkansas, killing two and injuring two more.  The accident resulted in a fire after alcohol spilled from a damaged rail car ignited, prompting evacuation of about 500 people from nearby homes.  The trains were carrying toxic chemicals, but none of the cars carrying the toxic chemicals are believed to have been breached during the accident.

The National Transportation Safety Board (NTSB) is currently investigating this accident, but an initial Cause Map, or visual root cause analysis, can still be built to help document and illustrate the information that is known.  One of the benefits of a Cause Map is that it can easily be expanded to incorporate information as it becomes available.  The first step of the Cause Mapping process is to fill in an Outline with the basic information for an incident.  In addition, anything that was different at the time of accident is listed.  How the incident impacts the overall goals is also documented on the bottom of the Outline.

Like many incidents, there are a number of goals that were impacted by this train collision.  The safety goal is obviously impacted by two fatalities and injuries.  The property goal is impacted because of the significant damage to the trains and freight.  The labor/time goal is impacted because of the response effort and investigation that are required as a result of the accident. Potential impacts or near misses should also be documented so the potential release of toxic chemicals is considered an impact to the environmental goal.

The second step is to perform the analysis by building the Cause Map.  To build the Cause Map, start with one impacted goal and ask “why” questions.  Each answer is added to the Cause Map.  Each impacted goal should be considered and the cause boxes should all connect at some location on the Cause Map.  Starting with the safety goal in this example, the first question would be: why were two people killed?  This occurred because there was a train collision.  The trains collided because they were traveling toward each other on the same track.  No details have been released about how the trains ended up on the same track.  The trains’ daily recorders (which provide information about the trains’ speed, braking and throttle) have been found and will be analyzed by investigators. The NTSB has stated that they will be looking into a number of factors such as the train signals and fatigue since the accident occurred late at night.

The final step in the Cause Mapping process is to develop solutions that can be implemented to reduce the risk of a similar problem recurring in the future.  Since the investigation is ongoing, talk of solutions is premature at this point.  Once more is known about the causes that contributed to this issue, the lessons that are learned can be used to develop solutions.

Root Cause Analysis - Incident Investigation

DELAY OF RECALL REPAIRS FIRES UP NHTSA

By ThinkReliability Staff

On June 18, 2013, the manufacturer of Jeep Grand Cherokee and Liberty sport-utility vehicles (SUVs) recalled 1.56 million vehicles due to a risk of fuel tank fires during rear-end collisions. At the time of the recall, the National Highway Traffic Safety Administration (NHTSA) linked 51 deaths to the fuel tank fires. Although a fix was accepted in January, parts won’t be available to owners until August.

The NHTSA is concerned about this delay. Says O. Kevin Vincent, NHTSA Chief Counsel, “For many owners, a recall remedy deferred by parts availability easily becomes a defect remedy denied. Moreover, additional delays in implementing this recall with inure to Chrysler’s benefit at the expense of vehicle owner safety.”

Even without full information, a Cause Map can begin to develop the cause-and-effect relationships that led to an issue. As more information is provided, more detail can be added to the Cause Map.

The analysis begins by determining the impacts to the organization’s goals. In this case, the safety goal is impacted by the 51 deaths that were determined to have resulted from gasoline fires as a result of the recall issue as well as 4 additional deaths that have occurred since the recall, according to the executive director of watchdog group Center for Auto Safety. The delay in the repairs for the recall issue can also be considered an impact to the customer service and production goals.

Beginning with one of the impacts to the goals, asking “why” questions builds the Cause Map, a visual root cause analysis. Beginning with the deaths that have occurred as a result of the recall issue since the recall took place, asking “why” questions helps determine that the deaths resulted from the issue at the heart of the recall (the increased risk for gasoline fires) and the delay in repairs from the recall. (Had the repairs been implemented more quickly, the number of deaths as a result of the issue may have been reduced.)

The increased risk of gasoline fires occurs from an increased risk of fuel tank rupture in the event of a rear-end collision because the fuel tank, in an unusual design, is located behind the rear-most axle, which provides inadequate protection. The fix for the recall issue is to add a trailer hitch, which provides an additional distance between another vehicle and the fuel tank in a rear-end collision (but it should be noted will protect only against “lower to medium-speed rear-end crashes”).

Although the addition of trailer hitches was recommended by the manufacturer at the time of the recall, a supplier was not selected until December. The manufacturer has stated that it was finding new suppliers to deal with the higher-than-normal demand for these parts. It’s also possible that the manufacturer was waiting for the NHTSA to approve the fix, which occurred in January. The NHTSA was doing additional testing to ensure that the fix would be effective. After the supplier was selected, it took nearly two months for a purchase order to be issued and five months for production to begin. The reasons for this part of the delay are unknown, and are expected to be provided to the NHTSA near-term.

The delay starting production is one thing; another concern is the amount of time it will take before enough parts are available. The supplier originally selected could manufacture 1,323 Liberty trailer hitches and 882 Grand Cherokee trailer hitches a day, meaning that if all 1.56 million vehicle owners participated in the recall, it would take 4.7 years to produce enough trailer hitches. Currently, legal requirements are only that manufacturers are required to make repairs in a “reasonable time”, although most manufacturers begin repairs within about 60 days of notifying the NHTSA. This case may force the NHTSA to define what a “reasonable time” actually is.

The latest update from Chrysler is that the trailer hitch supplier has increased production capacity and will be able to meet the demand by March of 2015. Chrysler also said that the NHTSA over-estimated the number of hitches required for the recall because the calculations didn’t account for vehicles that are no longer in use or those already equipped with hitches.

To view a timeline, Outline and Cause Map of this issue, please click “Download PDF” above. Or, click here to learn more.

 

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Root Cause Analysis - Incident Investigation

Nearly 2.6 million GM Vehicles Recalled, Costs Soar to 1.3 Billion

By Kim Smiley

During the first quarter of 2014, General Motors (GM) recalled 2.6 million vehicles due to ignition switch issues tied to at least 13 deaths.  Costs associated with the issue are estimated to be around $1.3 billion and, possibility even more damaging to the long term health of the company, is the beating the company’s reputation has taken.

The ignition switch issues are caused by a small, inexpensive part called a switch indent plunger.  An ignition switch has four main positions (off, accessories, on, and start) and the switch indent plunger holds the ignition switch into position.  In the accidents associated with the recent recall, the ignition switch slipped out of the on position and into the accessories position because the ignition switch plunger didn’t have enough torque to hold it in place.  When the ignition is put into the accessories mode, the car loses both power steering and power braking, and the air bags won’t inflate.  It’s easy to see how a situation that makes a car less safe and more difficult to control can quickly create a dangerous, or even deadly, situation.  Additionally, it’s important to know the problem is most likely to occur when driving on a bumpy surface or if a heavy key ring is pulling on the key.

The other key element of this issue is how the problem has been handled by GM.  There are a lot of hard questions being asked about what was known about the problem and when it was known.  It is known that the faulty part was redesigned in 2006 to address the problem, but the new design of the part wasn’t given a new part number as would normally be done.  Multiple federal inquiries are working to determine when it was known that the faulty parts posed a danger to drivers and why there was such a long delay before a recall was done.  The fact that the redesigned part wasn’t assigned a new part number has also lead to questions about whether there was an attempt to cover up the issue. GM is not civilly liable for deaths and injuries associated with the faulty ignition switches because of its 2009 bankruptcy, but the company could potentially be found criminally liable.

No company ever wants to recall a product, but it’s important to remember that how the recall is handled is just as important as getting the technical details right.  Consumers need to believe that a company will do the right thing and that any safety concerns will quickly and openly be addressed.  Once consumers lose faith in a company’s integrity the cost will be far greater than the price of a recall.

If you drive a GM car, you can get more information about the recall here.  The recalled models are Chevrolet Cobalts and Pontiac G5s from the 2005 through 2007 model years; Saturn Ion compacts from 2003 through 2007; and Chevrolet HHR SUVs, and Pontiac Solstice and Saturn Sky sports cars from 2006 and 2007.

To view the Outline and Cause Map showing the root cause analysis of this issue, please click “Download PDF” above.  Or click here to read more.

Root Cause Analysis - Incident Investigation

Risks of Future Landslides – and Actual Past Landslides – Ignored

By ThinkReliability Staff

Risk is determined by both the probability of a given issue occurring, and the consequence (impact) if it does. In the case of the mudslide that struck Oso, Washington on March 22, 2014, both the probability and consequence were unacceptably high.

The probability of a landslide happening in the area had not only been well-documented in reports as far back as 1951, the same area where dozens were killed on March 22 had experienced 5 prior landslides since 1949. The consequences of these prior landslides were less than the 2014 landslide because of the severity of the landslide, and because increased residential development meant more people were in harm’s way.

While the search for victims is still ongoing, the causes and impacts of the landslide are mostly known. This incident can be analyzed using a Cause Map, or visual root cause analysis, to show the cause-and-effect relationships that led to the tragic landslide.

First, we capture the background information and the impact to the goals in the problem outline, thereby defining the problem. The landslide (actually a reactivation of an existing landslide, according to Professor Dave Petley, in his blog) occurred around 10:40 a.m. on March 22, 2014 in an Oso, Washington residential area. As previously noted, there had been prior landslides in the area, and there were outdated boundaries used for logging permissions (which we’ll talk more about later). The safety goal was impacted due to the 30 known deaths, 15 and people missing. (Not all of the 27 have been identified, so the known dead and missing numbers may overlap. However, at this point, there is little hope that any additional rescues will take place.) The environmental goal was impacted due to the landslide and the customer service goal (insofar as the residents can be considered customers of their local area) was impacted due to the displacement of 30 families. Logging in an area that should have been protected impacts the regulatory goal. The estimated losses (of residences and belongings) are approximately $10 million, impacting the property goal and the massive search and a recovery effort impacts the labor goal.

Beginning with these impacted goals, asking ‘why” questions allows us to develop cause-and-effect relationships showing how the incident occurred. The safety goal was impacted because of the deaths and missing, which resulted from people being overcome by a landslide. In order for this to occur, the landslide had to occur, and the people had to be in the vicinity of the landslide.

As is known from history (see the timeline on the downloadable PDF), this area is prone to landslides. Previous reports identified the erosion of the area due to the proximity of the river as a cause of these landslides. An additional cause is water seepage in the area. Water seepage is increased when the water table rises from overly wet weather (as is typically found at the end of winter). Trees can help reduce water seepage by absorbing the water. When trees are removed, water seepage in an area can increase significantly. Because of this, removal of trees (for logging or other purposes) is generally restricted near areas prone to landslides. However, for reasons yet unknown, logging was permitted in what should have been a restricted area, because the maps used to allow it were outdated. Says the geologist who developed the new maps, “I suspect it just got lost in the shuffle somewhere.” Additionally, analysis by the Seattle Times, the logging went into the “old” restricted area as well. The State Forester is investigating the allegations and whether the logging played a role in the landslide.

Regardless of the magnitude of the impact of the logging and weather, the area was prone to landslides. Yet it was allowed to be developed, despite multiple reports warning of danger and five previous landslides. In fact, construction in the area resumed just three days after the last landslide in 2006. The 2006 landslide also interrupted a plan to divert the river farther from the landslide area. Despite all of this, the area built up (with houses built as recently as 2009) and those residents were allowed to stay. (While buying out the residents was under consideration, it was apparently dismissed because the residents did not want to move.) While officials in the area maintain that they thought it was safe, a long history of reports and landslides suggest otherwise.

If a lack of knowledge of the risk of the area continues to be a concern, aerial scanning with advanced technology (lidar) could help. Use of lidar in nearby Seattle identified four times the number of landslide zones that were spotted with aerial surveying, which is more typically used.

To view a summary of the investigation, including a timeline, problem outline and Cause Map, please click “Download PDF” above.

Root Cause Analysis - Incident Investigation

Metro Train Derails in the Bronx, Killing 4 and Injuring More Than 60

By Kim Smiley

Four passengers were killed and dozens more sent to the hospital after a metro train derailed in the Bronx early Sunday, December 1, 2013.  At the time of the accident, the train was carrying about 150 passengers and was traveling to Grand Central Terminal in New York City. The aftermath of the accident was horrific with all seven cars of the commuter train derailing. Metro-North has been operating for more than 30 years and this was the first accident that resulted in passenger deaths.

A Cause Map, or visual root cause analysis, can be built to help analyze this accident.  There is still a lot of investigative work that needs to be done to understand what caused the derailment, but the information that is available can be used to create an initial Cause Map.  The Cause Map can easily be expanded later to incorporate more information as it becomes available.  The first step when building a Cause Map is to fill in an Outline with the basic background information.  The impacts to the goals are also documented on the bottom of the Outline.  The impacted goals are then used to begin building the Cause Map.

In this example, the safety goal is clearly impacted because there were four fatalities and over 60 people injured.  The schedule goal is also significantly impacted because this portion of rail will be closed during most of the investigation.  The National Transportation Safety Board has estimated that the investigation will take 7 to 10 days.  The track closure is particularly impacting because this is a major artery into New York City with a ridership of 15.9 million in 2012.  Once the impacted goals are documented, the Cause Map itself is built by asking “why” questions.

So why did the train derail?  The details aren’t known yet, but there is still some information that should be documented on the Cause Map.  A question mark is included after a cause that may have contributed to an issue, but requires more evidence or investigation.  It’s useful to document these open questions during an investigation to ensure that all the pertinent questions are asked and nothing is overlooked.  (If it is determined that a cause didn’t play a role, it can be crossed out on the Cause Map to show that the cause was considered, but ruled out.)  Two factors that likely  played a role in the derailment are the speed of the train and the track design where the accident occurred.  There is a sharp curve in the track where the derailment happened.  Trains are required to reduce their speed before traveling it.  The latest reports from the investigation are that the train was traveling 82 mph in a 30 mph zone. The train operator has stated that the brakes malfunctioned and didn’t respond when he tried to reduce speed and that the train was traveling too fast over the curved track.

Investigators have recovered the data recorder from the train which will provide  more information and if there was a problem with the brakes.  Investigators will also interview all the relevant personnel and determine what happened to cause this deadly crash.  Once the investigation is completed, any necessary solutions can be implemented to reduce the risk that a similar accident occurs in the future.

To view a completed Outline and initial Cause Map of this incident, click on “Download PDF” above.