BOSTTON (SHNS) – Gov. Charlie Baker on Monday described himself as “really anxious” for federal investigators to publish early findings about a Green Line trolley crash on Friday and hinted it could take a month or longer to convene a new governing body for the MBTA.

The National Transportation Safety Board jumped into the investigation one day after the incident, in which a Green Line trolley traveling westbound on the B Branch struck another trolley from behind near Babcock Street and caused visible damage to both vehicles.

First responders provided medical attention to 25 people after the crash, according to the MBTA. Baker, who said he spoke with Transportation Secretary Jamey Tesler several times over the weekend, told reporters Monday that “thankfully, everybody there seems to be okay.”

The MBTA placed one Green Line driver, a seven-year veteran who was operating the front car on the trolley that struck the other vehicle from behind, on administrative leave. Other drivers have not been placed on leave.

“I’m really anxious to find out exactly what happened because this could have been a far more significant incident than it was given the estimates that are out there about how fast that train was traveling when it hit the other train,” Baker told reporters at a housing event in Everett.

MBTA officials have not said how fast the vehicles were traveling at the time of the impact. An NTSB spokesperson could not be reached Monday to respond to Baker’s comment about train speed.

Shuttle buses replaced trolleys in the affected area Friday night, and standard train service resumed Saturday morning.

“We will obviously get to the bottom of this. This should not happen, and we will find out why it happened and ensure it won’t happen again,” MBTA General Manager Steve Poftak told reporters at the scene Friday, according to audio a spokesperson provided.

The NTSB, a federal agency that examines transportation-related accidents and pipeline incidents such as the 2018 Merrimack Valley gas explosions, deployed four investigators with specialties in “operations, crashworthiness, and human performance” to the scene of the Green Line crash, a spokesperson said.

“At this early stage of an investigation, NTSB does not state a cause but will provide factual information when available,” NTSB spokesperson Jennifer Gabris said in a statement on Monday. “Investigations involving injuries and other major investigations currently take between 12 and 24 months to complete. A preliminary report is expected to be published in a few weeks.”

Baker said he expects the NTSB to be “the final word on this.” Once the federal team submits its findings, Baker said his administration will “work to move on the things that they recommend.”

The NTSB’s probe appears to be the agency’s first into an MBTA incident in more than a decade. Records show the NTSB’s last rail investigation in Massachusetts occurred in 2009, when a Green Line train collided with another train in an underground tunnel near Government Center, derailing both vehicles.

New Red and Orange Line trains remain out of passenger service after a March derailment on the Orange Line revealed an issue with side bearer pads on the cars manufactured by Chinese firm CRRC.

For much of the past six years, MBTA officials would provide updates in the aftermath of derailments and other incidents at regular meetings of the Fiscal and Management Control Board. However, the T is currently without its own dedicated governing body since lawmakers allowed the FMCB to expire on June 30, and the Department of Transportation’s board of directors will handle those duties in the interim.

After months of discussions about the composition of a new board, Baker last week signed a law creating a new, permanent seven-member MBTA board of directors to succeed the FMCB.

Baker will appoint five members: one with safety experience, one from a transit operations background, one with experience in finance, one T rider from an environmental justice population, and one who must come from a shortlist crafted by the Massachusetts AFL-CIO.

The MBTA Advisory Board, an independent agency representing the interests of cities and towns that help fund the T, will select a sixth member, and the secretary of transportation will serve as the board’s seventh member in an ex officio capacity.

Baker, who had also proposed his own iteration of a seven-member permanent board, said Monday it could take at least a month for the new board to come together.

“I really appreciate the House and the Senate coming to terms on that because it’s obviously an important issue for us,” he said. “But I think you can expect that sometime between now and — I hate putting a date on this, because I might get it wrong — I would just say sometime in the next four to six weeks, how’s that, we’ll probably put a team together and make our appointments.”