Two trains on the Massachusetts Bay Transit Authority’s Green Line in Boston crashed into each other on Friday at around 6 p.m., injuring 23 aboard, including the four train operators.
Both trains were heading west out of the city when one rear-ended the other. The MBTA said 65 to 70 people were on board both trains.
Here's a quick look at what we know so far about the crash and the ongoing investigation:
The two trains crashed on the Green Line track running along Commonwealth Avenue west of Boston University.
Service was suspended on the B Branch near Babcock Street after Friday’s collision as the two damaged trolleys were stopped on the track and injured victims were loaded into ambulances and taken to the hospital. None of the injuries were life-threatening.
Shuttle buses replaced trolleys between Kenmore and Washington Street stops for much of Friday evening following the collision while service was suspended. Commonwealth Avenue was also partially closed.
Green Line service between Kenmore and Washington Street was restored on Saturday after the trains involved in the crash were removed overnight.
What's the status of the investigation into the crash?
The cause of the crash remains under investigation.
"We will obviously get to the bottom of this. This should not happen, and we will find out why it happened and will ensure that it won't happen again," MBTA General Manager Steve Poftak said Friday.
Poftak added that investigators were looking into what speed the train in back was going. The speed limit for the trains is only 10 mph in the spot where the crash took place.
"The only conclusion we can draw is obviously, at some point, they became too close together," said Poftak. "That's a situation that should not happen."
The MBTA's safety department, along with state and federal oversight authorities, will also investigate whether this was operator error or mechanical malfunction, and what caused the two trains to bump so violently.
The National Transportation Safety Board announced Saturday morning that it is investigating the crash.
The Suffolk District attorney’s office is also looking into the collision, according to The Boston Globe.
Train operator suspended
Officials placed one of four operators on board the two Green Line trains on paid administrative leave.
Joe Pesaturo, a spokesperson for the MBTA, declined to identify the operator, but said the decision was made Saturday based on developments in the ongoing investigation, according to the Globe.
The employee, who has been with the MBTA for seven years, was operating the first car in the train that hit the other train from behind.
No other operators have been put on leave, the MBTA said.