By Kim Smiley
A standard commute quickly turned into a terrifying ordeal for passengers on a metro train in Washington, DC the afternoon of January 12, 2015. Shortly after leaving a station, the train abruptly stopped and then quickly filled with thick smoke. One passenger died as a result of the incident and 84 more were treated for injuries, predominantly smoke inhalation.
This incident 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 that contributed to an issue. The first step in the Cause Mapping process is to define the problem by filling in an Outline with the basic background information as well as documenting how the issue impacts the overall goals. For this example, the safety goal is clearly impacted by the passenger death and injuries. A number of other goals should also be considered such as the schedule goal which was impacted by significant metro delays. (To view an Outline and initial Cause Map for this issue, click on “Download PDF” above.)
So why were passengers injured and killed? Passengers were trapped on the train and it filled with smoke. It is unclear why the train wasn’t able to back up to the nearby station once the smoke formed and investigators are working to learn more. (Open issues can be documented on the Cause Map with a question mark to indicate that more evidence is needed.) There are also questions about the time emergency workers took to reach the train to aid in evacuation of passengers so this is another area that will require more information to fully understand. By some account, it took 40 minutes for firefighters to reach the trapped passengers.
Initial reports are that smoke was caused by an electrical arcing event, likely from the cables supporting the high voltage third rail used to power the trains. The specifics of what caused the arc are being investigated by the National Transportation Safety Board and will be released when the investigation is concluded. What is known is that there was significant smoke caused by the arc, but no fire. There have also been reports of water near the rails that may have been a factor in the arcing.
Eyewitness accounts of this incident are horrifying. People had little information and didn’t know whether there was fire nearby at first. They were told to remain on the train and await rescue, but the rescue took some time, which surely felt longer to the scared passengers. It won’t be clear what solutions need to be implemented to prevent similar problems in the future until the investigation is complete, but I think we can agree that metro officials need to work to ensure passenger safety going forward.