Copyright NBC10 Boston
The final report on an MBTA Green Line train derailing on its way from Cambridge to Somerville, Massachusetts, last year, injuring seven passengers, has determined a probable cause of the crash. The driver didn't stop the train at a stop signal, which led it to travel through a track switch that was still moving, causing the crash on Oct. 1, 2024, according to the National Transportation Safety Board. The agency said in the report that they didn't know why the operator traveled through the stop signal, which they identified as the probable cause. They noted that a contributing factor in what happened was the train traveling faster than the speed limit — it was going 36 mph as it entered a 10 mph zone on the Red Bridge interlocking, near Lechmere Station. In the wake of the crash, the NTSB said, the T reminded all its employees about the importance of following speed limits, lowered the speed limit by 5 mph on the lead-up to the Red Bridge, revised its operational testing program to include a more accurate way of tracking speed, added cameras on all equipment and began installing a way to alert train drivers that they're speeding. The MBTA is aiming to install automatic train control, which can slow or stop a train if a driver isn't responding to a signal, by 2028. "This investigation and MBTA’s response highlight the importance of deploying and maintaining effective systems to manage human error. These systems include robust oversight technologies and practices to identify and correct unsafe behaviors, and safety technologies like [automatic train control] to reduce or eliminate the consequences of mistakes," the report concludes. The MBTA said in a statement Thursday that it was reviewing the final report, and that it appreciated the investigation. The first phase of the Green Line Train Protection System, adding warning alarms for train operators, is set to go live by the end of the year. Earlier this month, the NTSB released a slew of documents in the case, including interviews with MBTA workers and officials, as well as maintenance records. Read all the documents available in the case here. Officials at the time said the crash took place in Cambridge; the NTSB gives the crash's location as Somerville.
