Stephen Poftak, the general manager of the MBTA, said the agency will work with the Federal Transit Administration as it reviews its safety procedures following several serious accidents over the past year.

His comment follows a letter sent the agency received from the FTA last month, and reporters obtained this week, in which the federal agency said it was "extremely concerned with the ongoing safety issues" at the agency. The FTA said it met with MBTA executives, but it was "unclear what actions the MBTA Board and executive team are implementing to prevent and address the system’s safety violations.”

“This is a process that we are pleased to cooperate with the FTA on," he said during an event on Tuesday. "I've pledged both externally to the FTA and I've made it clear to everyone at the MBTA that we want to engage and cooperate and collaborate in this process. If we identify any shortcomings related to safety, we will mitigate those immediately.”

Poftak went on to defend the agency’s actions implementing safety measures.

“We've almost doubled the size of the Safety Department in the last two years. ... We've launched over 100 initiatives in response to the safety review panel that reported out in December 2019," he said. "So we do have a really extensive record of the things that we're doing. And we look forward to sharing that with the FTA and getting their feedback on what they think is effective and if there are any gaps.”

The most recent serious accident involved a passenger who was killed after his arm became caught in a door while exiting a Red Line train at the Broadway station. The National Transportation Safety Board determined the railcar had a faulty door control system that allowed the train to move even with the door obstructed.

“We have identified the problem," Poftak said. "The problem was an anomaly. It was not in any other vehicle. We have put a mitigation in place so that problem can never happen again. And we've also changed our inspection protocol."

Other accidents involved a malfunctioning crossing gate in Wilmington that led to the death of a woman motorist crossing the tracks, a Green Line collision last July that sent nine people to the hospital, the collapse of an escalator at Back Bay station which left several people injured, and a slow-speed Red Line derailment in September in which no one was hurt.

Federal transit officials will meet with T leaders this week to kick off a safety investigation into the agency.

While Poftak said it is not "unprecedented" for the FTA to expand its safety oversight role, he could not identify a previous instance in which the federal agency pursued such a "formalized process."

Boston Mayor Michelle Wu, who rides the T regularly and campaigned on a platform of eventually making the system fare-free, embraced news of the federal agency’s inspection and increased oversight.

“This is the cost of deferred maintenance when we delay the investments that are needed, when we wait to take action, the costs come down the road," she told reporters Tuesday. “We know that the T is working very hard to be proactive about identifying incidents, but it’s always better safe than sorry in terms of welcoming the partnership from other levels of government to provide that oversight and accountability as well.”

GBH reporter Saraya Wintersmith contributed reporting.