NTSB: Green Line trolley went through stop sign before crash

The Green Line trolley that smashed into an out-of-service train, derailing both, in Somerville a month ago was going faster than the speed limit and went through a stop sign just before the crash, a preliminary report found.

The National Transportation Safety Board on Thursday released an initial report from its ongoing investigation into the Feb. 9 collision and derailment of two MBTA trains at the East Somerville Station. The crash at around 12:20 a.m. left two passengers and four crew members with non-life-threatening injuries and the T estimated damage to its equipment at roughly $6.6 million, the NTSB said.

"Shortly before the accident, the striking train departed Medford/Tufts Station and made three station stops without incident before approaching East Somerville Station, where the out-of-service train was stopped awaiting routing into MBTA's Inner Belt Yard. A preliminary review of event recorder and signal data indicates the striking train was traveling about 32 mph when it entered a 25-mph zone, passed a red (stop) signal and entered the 10-mph zone in the station where it collided with the stationary out-of-service train," the NTSB said.

The NTSB said that its future investigative activity related to the Green Line crash "will focus on vehicle crashworthiness; human performance; internal and external safety oversight; and operating procedures."

A spokesperson for the T said Thursday that the agency was still reviewing the NTSB's report, but agrees with its initial findings.

"The MBTA concurs with the facts established in the NTSB's preliminary report. The train operator remains out of service while the MBTA Safety Department completes its own investigation," the T's statement said. "With the safety and well-being of MBTA riders and employees of the utmost importance, the MBTA has been laser-focused on improving safety at all levels and maintaining a strong emphasis on compliance with Green Line operating rules, including adherence to posted speed limits."

The T has, since it was recommended by the NTSB about 15 years ago, been working to implement a train safety feature designed for the Green Line. The Green Line Train Protection System is meant to help prevent train-to-train collisions, rein in trolley speeding, and reduce the risk of operators running red lights on the tracks.

A February presentation from T officials showed that the first phase of the GLTPS — in which the system would notify the operator of an impending train collision or speed violation — is expected to be complete in December. The second phase — in which the system could automatically slow or stop a train if warnings are ignored — is expected to be completed by 2028.