Category Archives: Root Cause Analysis – Incident Investigation

Root Cause Analysis - Incident Investigation

Distraction Related Accidents: Eyes on Road, Hands on Wheel, AND Mind on Task

By  Sarah Wrenn

Admit it – you’ve checked your phone while driving.  We’ve likely all been guilty of it at some point.  And despite knowing that we’re not supposed to do it – it’s against the law in most states and we understand that the distraction increases our risk of having an accident – we still do it.  Why?

On March 31, 2015, the National Transportation Safety Board (NTSB) held its first roundtable discussion on distractions within the transportation industry.  In 2015, the NTSB added “Disconnect from Deadly Distractions” to its “Most Wanted List of Transportation Safety Improvements for 2015.”  This list represents the NTSB’s priorities to increase awareness and support for key issues related to transportation safety.  Other critical topics include “Make Mass Transit Safer” and “Require Medical Fitness for Duty.”

Representatives from all modes of transportation, technology, law enforcement, insurance, researchers, advocates, and educators came together for discussion related to distractions facing vehicle operators.

“New technologies are connecting us as never before – to information, to entertainment, and to each other,” said NTSB Member Robert Sumwalt. “But when those technologies compete for our attention while we’re behind the wheel of a car or at the controls of other vehicles, the results can be deadly.”

Digging into the causes

So let’s take a look at some of the causes related to an accident where the operator is distracted.  In addition to the accident occurring because of the distraction, the level of driver expertise is also a factor.  A large effort has been made to raise awareness and provide education to teenage drivers.  This is in part because, as novice drivers, they have a more limited exposure to driving situations and may not have the ability to react as a more skilled driver.

Operators become distracted

We also want to understand the causes that led to the operator being distracted.  There is a distraction type (or mode) that was introduced, the duration of the distraction, and the individual’s inability to ignore the distraction that result in the operator distraction.  While the type of distraction plays a large role in taking the operator’s eyes off the road, hands off the wheel or mind off the task, the duration of the distraction also is a key factor.  For example, while one’s eyes remain on the road during a phone call, the duration of that call disengages the brain from the task for more time than the act of dialing the phone.  This is not to say that one of these actions is more or less impactful; it is important to note that they both play a role in distracting the individual.

It’s not just the text that is distracting

There are three primary forms of distractions – Visual (taking eyes off of the road), Manual (taking hands off of the wheel), and Cognitive (taking mind off of the task).  Visual and manual types of distractions are very easy to define and generally recognized as risky behaviors while operating a vehicle.  Cognitive distractions are less tangible and therefore more difficult to define.  Research and studies generally define cognitive distractions as when the individual’s attention is divided between two or more tasks.  While technology and activities such as texting or talking on the phone are typically identified as the primary forms of distraction, it is interesting to note that cognitive distractions such as allowing your mind to wander while operating a vehicle can be just as risky.  The AAA Foundation released a 2013 study “Measuring Cognitive Distraction in the Automobile.”  The study rates various tasks such as using a hands-free cell phone and listening to the radio according to the amount of cognitive workload imposed upon an operator.  The study concludes that “while some tasks, like listening to the radio, are not very distracting, others – such as maintaining phone conversations and interacting with speech-to-text systems – place a high cognitive demand on drivers and degrade performance and brain activity necessary for safe driving.”

The forum discussed the concept that ability to multi-task is actually a myth, with evidence and data to conclude that for certain types of activities multi-tasking is not only difficult, but impossible.  For example, tasks such as navigation and speech require the use of the same circuits within the brain.  As such, the brain cannot do both tasks at once.  Instead, the brain is switching between these tasks, resulting in a reduction of focus on the primary task (driving) while attempting to perform a secondary task (speaking).  Therefore, attempting to multi-task introduces a cognitive distraction that increases the risk of unsafe driving.

Just ignore it

Why don’t we just ignore the temptation to become distracted?

Our brains function by releasing serotonin and dopamine when an action occurs that makes us feel good.  Dr. Paul Atchley of the University of Kansas stated: “There is nothing more interesting to the human brain than other people.  I don’t care how you design your vehicle or your roadways, if you have technologies in the vehicle that allow you to be social, your brain will not be able to ignore them.  There are only two things we love, serotonin and dopamine.  The two reward chemicals that come along with all those other things that make us feel good.  There is really nothing more rewarding to us than the opportunity to talk to someone else.”

Surveys performed by various organizations have revealed a large percentage of people (sometimes 3 out of 4) that will admit to being distracted while driving.  Meanwhile, a staggering percent (upwards of 90%) will rationalize the behavior which is a sign of addiction.

Finally, the level of brain development controls our ability to respond to distractions.  For example, a teenager has a less developed fontal cortex than an adult which means, as Dr. David Strayer of the University of Utah explains: “Teens’ frontal cortex, the parts of the brain that do decision-making in terms of multitasking, are underdeveloped.”  Much of the focus on distracted driving is focused on teens and this is justified as their brain development is not yet complete.  It is, however, important to note that this is not just an issue for teens who can’t be separated from their phones or seniors who don’t understand them; this is an issue that crosses all demographics.  Level of brain development is just one factor.

So what can we do?

At the end of the day, we want to identify solutions that are going to effectively reduce the risk of having accidents related to distractions from occurring.  While there will always be some risk, it is key to take a comprehensive approach to education, technology, and policy.  Programs like EndDD.org and stopdistractions.org are focused on bringing awareness, education, and training to youth and adults about the risks of operating vehicles while distracted.  Technology can also be used in a variety of ways to reduce the risk of these types of accidents.  Sensors can be built into vehicles to identify distractions and provide alerts to drivers or apps can be used to disable functions of technology so the receipt of calls and texts are delayed.  Finally, establishing policies and laws that are realistic and enforceable is important so that individuals are held accountable for risky behaviors before an accident occurs.  No one single solution is going to reach everyone and no one single solution is going to eliminate the risk of deadly accidents.  Each one of these solutions has limitations, but they also have advantages.  With a balanced approach to raise awareness and education, provide resources and tools to drivers, and change the culture of what is acceptable while driving, we can reduce the amount of accidents and save lives.

References:

NTSB Roundtable: Disconnect from Deadly Distractions held March 31, 2015, from 9:00 a.m. – 4:00 p.m.

AAA Foundation: Measuring Cognitive Distraction in the Automobile, June 2013

Root Cause Analysis - Incident Investigation

THE WOEFUL TALE OF JACK & JILL

By Jon Bernardi

There has been a disturbing rise of injuries once thought to have been eradicated. Several federal and state agencies are considering legislation to address the very dangerous injuries from the gathering of liquid di-hydrogen oxide from certain unprotected hills and wells. Once upon time became the last straw, when siblings Jack and Jill fetched the ill-fated pail. Not only were crowns injured, but various homeopathic remedies were implemented with little consequence except to other participants, notably Jill.

What caused this unfortunate turn of events?

That question can be answered by building a Cause Map, a visual root cause analysis.  In the Cause Mapping process, the first step is to fill in an Outline with the background information for an issue as well as how the problem impacts the goals.  In this example, the aforementioned fetching impacts quite a number of goals: Safety as crowns were broken; environmental, the spilled di-hydrogen oxide; regulatory, child corporal punishment and child labor laws; customer service, no di-hydrogen oxide available for multiple purposes; production, the delay of supper; and labor, the time needed for medical attention.

Fortunately no property was lost as the well-made bucket survived intact.  Once we have filled out the Outline, the next step is to ask “why” questions to find the different causes that contributed to the problem being analyzed.

So why were they going up a hill? This presents us with a number of potential paths of exploration as to why the well was at the top of a hill. Even without knowing a detailed answer we know that a potential solution would be to get them hooked up an established di-hydrogen oxide system as soon as possible!

Why was there no protection? Broken crowns are a serious affair. This combined with the potential for other injuries from the fractious “tumbling down” incident leaves us to wonder how the well could be constructed in such a manner.

These are areas for further exploration. Even with the unanswered questions we are still able to propose several solutions to ensure that child labor laws are not ignored, hills are properly protected, and home remedies are carefully considered.

To view an Outline and a high level Cause Map for this issue, click on “Download PDF” above.

Root Cause Analysis - Incident Investigation

Houston Ship Channel Closed After Ships Collide

By Kim Smiley

On March 9, 2015, two large ships collided in the Houston Ship Channel, one of the busiest waterways in the United States.  There were no major injuries reported, but the accident resulted in the release of methyl tertiary-butyl ether, commonly called MTBE, a chemical that is used as a fuel additive.  The clean-up and investigation of the collision closed the channel from the afternoon of March 9 until the morning of March 12.

At the time of the collision, the tanker Carla Maersk was traveling outbound in the channel transporting MTBE.  The bulk carrier Conti Perido was heading inbound with a load of steel.  Both ships were significantly damaged by the collision and three cargo tanks ruptured on the Carla Maersk, spilling the MTBE. Limited information has been released about what caused the accident, but a National Transportation Safety Board investigation is underway.  Initial reports are that both vessels were traveling at about 9 knots, which is typical for this stretch so excessive speed does not appear to be a cause.  It has also been reported that it was foggy at the time of the accident which may have played a role in the accident.

An initial Cause Map can be built using the information that is available.  The first step in the Cause Mapping process is to fill in an Outline with the basic background information along with the impacts to the goals.  Like many incidents, this collision impacted several different goals.  The safety goal was impacted because MTBE is toxic and has the potential to cause injuries.  The environmental goal was clearly impacted by the release of MTBE.  The multiple-day closure of the Houston Ship Channel is an impact to the production/schedule goal and the impact to local businesses resulting from closure is an impact to the economic goal.  The damage to the ships is an impact to the equipment goal.

On the outline, there is also a line to record the frequency of how often a similar event has occurred.  It’s important to consider the frequency because a small problem that occurs often may very well warrant a more detailed investigation than a small problem that has only been seen once.  In this example, there have been previous ship collisions.  This accident was the second ship collision to occur in the channel in a week.  Two large ships bumped on March 5, 2015, which did not result in any injuries or pollution.

Release of MTBE is a significant concern, but the impacts of this ship collision could easily have been worse.  MTBE is volatile and flammable so there could have been a fire or the ships could have been carrying something more dangerous.  It may be difficult to get the data, but it would be interesting to know how many near misses have occurred between ships traveling in the channel. The frequency that accidents are occurring needs to be considered along with the details of any individual incident when conducting an investigation. Two collisions in a week is a pretty clear indication that there is potential for more to occur in the future if nothing is changed.

Root Cause Analysis - Incident Investigation

Plane Narrowly Avoids Rolling into Bay

By ThinkReliability Staff

Passengers landing at LaGuardia airport in New York amidst a heavy snowfall on March 5, 2015, were stunned (and 23 suffered minor injuries) when their plane overran the runway and approached Flushing Bay.  The National Transportation Safety Board (NTSB) is currently investigating the accident to determine not only what went wrong in this particular case, but what standards can be implemented to reduce the risk of runway overruns in the future.

Says Steven Wallace, the former director of the FAA’s accident investigations office (2000-2008), “Runway overruns are the accident that never goes away.  There has been a huge emphasis on runway safety and different improvements, but landing too long and too fast can result in an overrun.”  Runway overruns are the most frequent type of accident (there are about 30 runway overruns due to wet or icy runways across the globe every year), and runway overruns are the primary cause of major damage to airliners.

Currently, the NTSB is collecting data (evidence) to aid in its investigation of the accident.  The plane is being physically examined, and the crew is being interviewed.  The data recorders on the flight are being downloaded and analyzed.  While little information is able to be verified or ruled out at this point, there is still value in organizing the questions related to the investigation in a logical way.

We can do this using the Cause Mapping method of root cause analysis, which organizes cause-and-effect relationships related to an incident.  We begin by capturing the impact to an organization’s goals.  In this case, 23 minor passenger injuries were reported, an impact to the safety goal.  There was a fuel leak of unknown quantity, which impacts the environmental goal.  Customer service was impacted due to a scary landing and evacuation from the aircraft via slides.  Air traffic at LaGuardia was shut down for 3 hours, impacting the production goal.  Both the airplane and the airport perimeter fence suffered major damage, which impacts the property/equipment goal.  The labor goal was also impacted due to the response and ongoing investigation.

By beginning with an impacted goal and asking “why” questions, we can begin to diagram the potential causes that may have resulted in an incident.  Potential causes are causes without evidence.  If evidence is obtained that supports a cause, it becomes a cause and it is no longer followed by a question mark.  If evidence rules out a cause, it can be crossed out but left on the Cause Map.  This reduces uncertainty as to whether a potential cause has been considered and ruled out, or not considered at all.

In this case, the NTSB will be looking into runway conditions, landing procedures, and the condition of the plane.   According to the airport, the runway was cleared within a few minutes of the plane landing, although the crew has said it appeared all white during landing.  The National Weather Service reported 7″ of snow in the New York area on the day of the overrun.  Procedures for closing runways or aborting landings are also being considered.  Just prior to the landing, other pilots who had recently landed reported braking conditions as good.

The crew has also reported that although the auto brakes were set to max, they did not feel any deceleration. The entire braking system will be investigated to determine if equipment failure was involved in the accident.  (Previous overruns have been due to brake system failures or the failure of reverse thrust from one of the engines, causing the plane to veer.)  The pilot also reported the automatic spoiler did not deploy, but they were deployed manually.

Also being investigated are the landing speed and position, though there is no evidence to suggest that there was any issue with crew performance.  As more information is released, it can be added to the investigation.  When the cause-and-effect relationships are better determined, the NTSB can begin looking at recommendations to reduce future runway overruns.

Root Cause Analysis - Incident Investigation

Train Derails in West Virginia

By Kim Smiley

On February 16, 2015, a train hauling 109 tank cars of crude oil derailed in Mount Carbon, West Virginia.  It has been reported that 27 tank cars in the train derailed.  Some of the tank cars were damaged and released an unknown amount of crude oil, resulting in a large fire.  Hundreds of families in the surrounding area were evacuated, but only one injury was reported.

The accident investigation is still ongoing, but what information is known can be used to build an initial Cause Map, a visual format for performing a root cause analysis.  The Cause Map can be easily expanded as needed to document additional information as it becomes available.

The first step in the Cause Mapping process is to fill in an Outline with the basic background information for the issue as well as how the overall goals were impacted. In this example, there were many impacted goals.  The safety goal is impacted because there was an injury, the property goal is impacted because of the damage to the train, the environmental goal is impacted because of the release of oil, etc.  Once the Outline is complete, the Cause Map itself is built by starting with an impact to a goal, asking “why” questions, and laying out all the causes that contributed to an issue.

The significant aftermath of this derailment is known, but little has been released about what specifically caused the train to derail.  It was snowing heavily at the time of the accident, which may have played a role, but since more evidence is needed, a “?” is included on the Cause Map.  Data from the digital data recorder has shown that the train was not speeding at the time of the accident, which has been a factor in previous derailments.  Another fact worth noting is that the damaged train cars were a newer design that incorporated modern safety upgrades.

With so many unknowns, the Federal Railroad Administration is conducting a full-scale investigation to determine exactly what happened.  The damaged tank cars, track, and other components along with relevant maintenance and inspection records will be all be analyzed to better understand this derailment.

Unfortunately, crude oil train accidents are predicted to become increasingly common as the volume of flammable liquids being transported by rail continues to rise.  According to the Association of American Railroad, 40 times more oil was transported by rail in 2012 than in 2008. Hopefully, the lessons learned from this derailment can be used to help reduce the risk of future rail accidents.

To view the Outline and initial Cause Map for this accident, click on “Download PDF” above.

Root Cause Analysis - Incident Investigation

Early Problems with Mark 14 Torpedoes

By Kim Smiley

The problems with Mark 14 torpedoes at the start of World War II are a classic example that illustrates the important of robust testing.  The Mark 14 design included brand new, carefully guarded technology and was developed during a time of economic austerity following the Great Depression.  The desire to minimize costs and to protect the new exploder design led to such a limited test program that not a single live-fire test with a production model was done prior to deploying the Mark 14.

The Mark 14 torpedo design was a step change in torpedo technology. The new Mark VI exploder was a magnetic exploder designed to detonate under a ship where there was little to no armor and where the damage would be greatest.  The new exploder was tested using specially instrumented test torpedoes, but never a standard torpedo. Not particularly shocking given the lack of testing, the torpedoes routinely failed to function as designed once deployed.

The Mark 14 torpedoes tended to run too deep and often failed to detonate near the target. One of the problems was that the live torpedoes were heavier than the test torpedoes so they behaved differently. There were also issues with the torpedo’s depth sensor.  The pressure tap for the sensor was in the rear cone section where the measured pressure was substantially less than the hydrostatic pressure when the torpedo was traveling through the water.  This meant that the depth sensor read too shallow and resulted in the torpedo running at deeper depths than its set point.  Eventually the design of the torpedo was changed to move the depth sensor tap to the mid-body of the torpedo where the readings were more accurate.

The Mark 14 design also had issues with premature explosions.  The magnetic exploder was intended to explode near a ship without actually contacting it.  It used small changes in the magnetic field to identify the location of a target. The magnetic exploder had been designed and tested at higher latitudes and it wasn’t as accurate closer to the equator where the earth’s magnetic field is slightly different.

In desperation, many crews disabled the magnetic exploder on Mark 14 torpedoes even before official orders to do so came in July 1943.  Use of the traditional contact exploder revealed yet another design flaw in the Mark 14 torpedoes.  A significant number of torpedoes failed to explode even during a direct hit on a target.  The conventional contact exploder that was initially used on the Mark 14 torpedo had been designed for earlier, slower torpedoes.  The firing pin sometimes missed the exploder cap in the faster Mark 14 design.

The early technical issues of the Mark 14 torpedoes were eventually fixed and the torpedo went on to play a major role in World War II.  Mark 14 torpedoes were used by the US Navy for nearly 40 years despite the early issues.  But there is no doubt that it would have been far more effective and less painful to identify the technical issues during testing rather than in the field during war time.  There are times when thorough testing may seem too expensive and time consuming, but having to fix a problem later is generally much more difficult.  No one wants to waste effort on unnecessary tests, but a reasonable test program that verifies performance under realistic conditions is almost always worth the investment.

To view a high level Cause Map of the early issues of the Mark 14 torpedoes, click “Download PDF”.

You can also learn more about the torpedoes by clicking here and here.

Root Cause Analysis - Incident Investigation

Deadly Train-Car Collision

By Kim Smiley

On February 3, 2015, an SUV was struck by a commuter train near Valhalla, New York.  The driver of the vehicle and 5 train passengers were killed in the accident.  The National Transportation Safety Board (NTSB) is investigating the accident to determine what went wrong.

An initial Cause Map, a visual root cause analysis, can be built to analyze and document what is known about this train-car collision.  A Cause Map visually lays out the cause-and-effect relationships that contributed to an issue and focuses on understanding all the causes, not THE root cause.  Generally, identifying more causes results in a greater number of potential solutions being considered.

So why did the train hit a vehicle?  Eyewitnesses have stated that the SUV was hit by a crossing gate as it descended.    It is not clear why the SUV didn’t stop prior to entering the railroad crossing area. The driver pulled the SUV forward onto the tracks rather than backing up and the train struck the vehicle shortly after.  Investigators don’t know why the driver stopped on the tracks, but initial reports are that all safety features, such as the crossing gate, signs and train horn, were functioning properly at the time of the accident.

Unfortunately, it’s not unusual for passengers in a vehicle struck by a train to be injured or killed, but it is less common for fatalities among the train passengers.  Investigators are working to determine what made this accident particularly dangerous for train passengers.  The NTSB plans to use information about the passengers’ injuries and a diagram of where people were sitting on the train to try to understand what happened during the collision.  Post-accident photos of the train show that significant fire damage occurred, likely fueled by the gas in the SUV.

One of the open questions is whether the electrified third rail contributed to the accident and subsequent injuries. Metro-North uses an unusual “under-running” third rail design where power is taken from the bottom of the rail.  During the collision, 400 feet of the third rail broke apart and 12 pieces pierced both the SUV and the train. This rail design uses a metal shoe that slips underneath the third rail and some think that the force of the collision may have essentially pried up the rail and threw it into the train and vehicle.

Open questions can be documented on the initial Cause Map with a question mark.  As more information becomes available, the Cause Map can quickly be updated.  Typically, Cause Maps are built in Excel and different versions can be saved as different sheets to document the investigation process.

Click on “Download PDF” above to view an initial Cause Map of this accident, built from the information in the media articles on the accident.

Root Cause Analysis - Incident Investigation

TransAsia Plane Crashes into River in Taiwan

By Kim Smiley

On February 4, 2015, there were 53 passengers onboard TransAsia Airways Flight 235 when the plane crashed into the Keelung River shortly after taking off from the Taipei Shonshan Airport.  There were 15 survivors from this dramatic crash where the plane hit a bridge and taxi cab prior to turning upside down before hitting the river. (The crash was caught on video by dash cameras from a vehicle on the bridge and can be seen here.)

Investigators are still working to determine exactly what happened, but some early findings have been released.  The plane involved in this crash was a turboprop with two engines.  This model of plane can fly safely with only one engine, but both engines had issues immediately prior to the crash so the pilots were unable to control the plane.

Data from the flight recorder shows that the right engine idled 37 seconds after takeoff.  No details about what caused the problem with the right engine have been made available.  The initial investigation findings are that the left engine was likely manually shut down by the pilots.  It’s not clear why the functioning engine would have been intentionally shut down. Early speculation is that it was a mistake and that the pilots were attempting to restart the idled right engine when they hit the switch for the operating left engine.

The investigation into the crash is ongoing and the final report isn’t expected to be released for about a year, but based on the initial findings, a few solutions to help reduce the likelihood of future crashes have already been implemented.  TransAsia has grounded most of its turboprop aircraft pending additional pilot instruction and requalification because it is believed that pilot action may well have contributed to the deadly accident.  More than 100 domestic flights have been canceled as a result.  Additionally, Taiwan’s Civil Aeronautic Administration has announced that the carrier will be banned from adding new international routes for 12 months.  A previous crash in July 2014 had already tarnished TransAsia’s reputation and this latest disaster will certainly be scrutinized by the authorities.

An initial Cause Map, a visual root cause analysis, can be built to analyze the information that is available on this crash and to document where there are still open questions.  To view a Cause Map and Outline of this incident, click on “Download PDF” above.

Root Cause Analysis - Incident Investigation

Fatal Bridge Collapse Near Cincinnati

By Kim Smiley

On the evening of January 19, 2015, an overpass on Interstate 75 near Cincinnati collapsed, killing one and injuring another.  The overpass was undergoing construction when it unexpectedly collapsed onto the road below it, which was still open to traffic.

This incident can be analyzed by building a Cause Map, a visual root cause analysis, to intuitively lay out the many causes that contributed to an accident by showing the cause-and-effect relationships.  Understanding all the causes that played a role, as opposed to focusing on a single root cause, expands the potential solutions that can be considered and can lead to better problem prevention.  A Cause Map is built by asking “why” questions and documenting the answers.

In this example, a construction worker was operating an excavator on the overpass when it collapsed.  When the bridge collapsed the worker was crushed by the steel beams he was moving.   The additional weight of evacuator and steel beams on the overpass likely contributed to the collapse.   The overpass was being demolished as part of a project to remake this section of the Interstate and a portion of the overpass had already been removed.  The work that had been done appears to have made the structure of the bridge unstable, but the construction company was not aware of the potential danger so the worker was operating on top of the overpass and the road beneath it was still open to traffic.

A truck driver traveling under the overpass at the time of collapse suffered only minor injuries, but came within inches of being crushed by the bridge. It really was simple luck that no other vehicles were involved.  Had the collapse happened earlier in the day when there was more traffic, the number of fatalities may very well have been higher.  As investigators review this accident, one of the things they will need to review is the fact that the road below the bridge was open to traffic at the time of the collapse.  An additional relevant piece of information is that the construction company had financial incentives to keep the road open as much as possible because they would be fined for any amount of time that traffic was disrupted.

In addition to the safety impacts of this accident, the overpass collapse dramatically impacted traffic on a busy road with an estimated 200,000 vehicles traveling on it daily.  It took nearly a day to get all lanes of the interstate cleaned up and reopened to traffic.  No one wants to close roads unnecessarily and the goal of minimizing traffic is an excellent one, but it has to be balanced with safety.  The collapse of the overpass wasn’t an unforeseeable random accident and the demolition needs to be done in a safe manner.

Root Cause Analysis - Incident Investigation

Prison Bus Collides With Freight Train

By Kim Smiley

On the morning of January 14, 2015, a prison bus went off an overpass and collided with a moving freight train.  Ten were killed and five more injured.  Investigators believe the accident was weather-related.

This tragic accident can be analyzed by building a Cause Map, a visual root cause analysis.  A Cause Map visually lays out the cause-and-effect relationships to show all the causes (not just a single root cause) that contributed to an accident.  The first step in the Cause Mapping method is to determine how the incident impacted the overall organizational goals.  Typically, more than one goal needs to be considered.  Clearly the safety goal was impacted because of the deaths and injuries.  The property goal is impacted because of the damage to both the bus and train (two train cars carrying UPS packages were damaged).  The schedule goal is impacted because of the delays in the train schedule and the impact on vehicle traffic.

The Cause Map itself is built by starting at one of the impacted goals and asking “why” questions. So why were there fatalities and injuries?  This occurred because there were 15 people on a bus and the bus collided with a train.  The bus was traveling between two prison facilities and drove over an overpass.  While on the overpass, the bus hit a patch of ice and slid off the road, falling onto a moving freight train that was passing under the roadway.  No one onboard the train was injured and the train did not derail, but it was significantly damaged.  The bus was severely damaged.

The prisoners onboard the bus were not wearing seat belts, as is typical on many buses.  They were also handcuffed together, although it’s difficult to say how much this contributed to the injuries and fatalities.

Useful solutions to prevent these types of accidents can be tricky.  The prison system may want to review how they evaluate road conditions prior to transporting prisoners.  This accident occurred early in the morning and waiting until later in the day when temperatures had increased may have reduced the risk of a bus accident.  Transportation officials may also want to look at how roads, especially overpasses, are treated in freezing weather to see if additional efforts are warranted.

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

You can also read our previous blogs to learn more about other train collisions:

Freight Trains Collide Head-on in Arkansas

Freight Train Carrying Crude Oil Explodes After Colliding with Another

“Ghost Train” Causes Head-on Collision in Chicago

Deadly Train Collision in Poland