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.