Robinson Lalin died in a Red Line tunnel just past Andrew station because he tried to exit the train through the one door on which a mechanism intended to keep the train from moving if it wasn't fully closed failed, the National Transportation Safety Board reported this morning.
In its brief initial report, in an investigation it says is ongoing, the NTSB says the MBTA checked all the doors on Red Line trains and found only the one in which Lalin got stuck was broken that way.
MBTA trains are designed and equipped with safety features to prevent them from moving when the passenger doors are obstructed. NTSB investigators examined and tested the railcar involved after the accident, identifying a fault in a local door control system that enabled the train to move with the door obstructed. The MBTA immediately initiated a fleet inspection looking for the identified fault in other railcars to prevent reoccurrence. The MBTA reported that no other similar faults were found during the inspection.
The report does not say whether the train operator visually checked the doors before starting the inbound train moving.
The bureau also summarized what happened as Lalin was trying to get off the train around 12:30 a.m. on April 10:
Surveillance video reviewed by National Transportation Safety Board (NTSB) investigators showed that the passenger attempted to exit the six-car train through the side passenger door of the railcar they were riding in as the train doors were closing. In the attempt to exit the train, the passenger’s right arm was trapped in the door. The train departed the station, dragging the passenger along the platform about 105 feet and onto the surface below, near the tracks.