BOSTON (State House News Service) - Federal investigators identified a Green Line operator's "loss of situational awareness" as the likely cause of a July 2021 Green Line collision, and their report about the incident published Thursday also appeared to reveal a lengthy delay to an overdue MBTA safety feature that could have prevented the crash.
Two and a half years after the incident that sent 24 passengers and three MBTA workers to local hospitals with minor injuries, the National Transportation Safety Board published its findings that concluded the driver's sudden acceleration and "loss of situational awareness" were the probable cause of the crash into another Green Line train and subsequent derailment, which caused about $2 million in damage.
Investigators did not find track defects or problems with either Green Line trolley involved, but they pointed out that a long-discussed safety feature could have played a crucial role.
More than a decade ago, federal officials recommended the MBTA install automated anti-collision technology on the Green Line, but that never happened.
MBTA leaders said following the 2021 crash they would accelerate the project timeline and bring the Green Line Protection Project online by 2023, but the NTSB said in its report that the agency in fact plans to have the system completed by June 2025.
T officials had not previously announced a two-year delay to the Green Line Protection system, and an MBTA spokesperson could not be reached for immediate comment Thursday evening.
As recently as Nov. 1 -- the last available date with the project webpage archived -- the MBTA described the target completion date for the anti-collision technology as "late 2023." On Thursday, the current version of that page listed the completion date as "June 2025."
"In this accident, the striking trolley was over-speeding by about 23 mph. MBTA's current operations and control system does not have an engineering feature that would automatically intervene and apply brakes to prevent trolleys from violating speed or separation policies," the NTSB wrote. "Had such a system been in place at the time of the accident, this collision would have been prevented."
The high-profile collision prompted then-Suffolk County District Attorney Rachael Rollins to open a criminal probe examining the MBTA and charge the operator, Owen Turner, with negligence.
Turner, who was not named in the NTSB report, told investigators he saw the other two-car set in front of him before crossing a bridge and slowed down to increase the space between the vehicles. But the situation quickly escalated.
"The operator told investigators that 'everything went black' after he observed the signal to proceed across St. Paul Street. He added that he did not know what happened but believed he had fallen asleep," the NTSB wrote. "The NTSB's review of event recorder data from both trolleys showed that the striking trolley accelerated under full power for about 500 feet between the passenger stop at St. Paul Street Station and the point of impact near Harry Agganis Street, reaching a speed of about 33 mph when it struck the other westbound trolley, which was traveling about 10 mph. The impact accelerated the struck trolley to about 24 mph and caused it to derail."
Turner was hired in September 2014 and had worked on the Green Line for less than a year before the crash, according to the NTSB. The federal agency said he had "eight documented disciplinary actions for six policy violations, including two actions for a previous accident involving a trolley hitting an automobile and two actions for speeding" and has since been terminated by the MBTA.
NTSB investigators concluded that Turner's "workload and work schedule were not contributors to fatigue on the day of the accident," and he tested negative for alcohol and drug intoxication.
"The investigation did not determine the cause of the operator's loss of situational awareness," NTSB wrote.
Event recorder data showed that Turner did not apply the trolley's brakes before impact and the master controller "was in the full-power position" at the moment of the crash, the NTSB wrote. The maximum speed limit on the Green Line is 25 mph and the limit through intersections is 10 mph, which Turner's train far exceeded.
The MBTA's glaring safety problems drew separate federal attention this year with a blistering Federal Transit Administration investigation that prompted multiple corrective action orders. Fixing the problems looms at or near the top of the to-do list for new Gov. Maura Healey, who said in her inaugural address Thursday she would use her first annual state budget to fund hiring 1,000 MBTA workers.
Written by Chris Lisinski