A Boston train caught on fire on a bridge over the Mystic River Thursday morning, leading several passengers to escape the flames through windows.
"This morning, an Orange Line train reported flames & smoke coming from its head car as it traveled across the bridge between Wellington & Assembly stations," the Massachusetts Bay Transportation Authority wrote in a statement shared on social media.
The MBTA added that "emergency personnel quickly responded, shutting down power, and safely assisting ~200 passengers from the train."
In a statement, an MBTA spokesperson told PEOPLE that while most of the passengers "were walked off the train," some people "did evacuate through windows." At a press conference, MBTA General Manager Steve Poftak said they believe that 4 windows were removed for self-evacuation.
Additionally, public safety personnel helped assist "a person who had jumped into the water after exiting the train," according to the MBTA.
Speaking with The New York Times, Nick Andreucci said that he was among a group of passengers who "jumped out" of a window when attempts to open up a door at the back of the train failed.
"Everyone started to freak out. You could see people coughing outside," one passenger told ABC Station WCVB, as another witness told the outlet that one woman panicked and jumped into the river below.
Never miss a story — sign up for PEOPLE's free daily newsletter to stay up-to-date on the best of what PEOPLE has to offer, from juicy celebrity news to compelling human interest stories.
"An unidentified female passenger jumped off the bridge into the river," Somerville Fire Chief Charles Breen said in a statement, according to the Boston Globe. "Our marine boat happened to be in the river for training and was on scene immediately."
"The woman refused to get into the boat. She was provided a life jacket and proceeded to swim to shore…then she walked away," Breen added.
In a statement shared on social media, the MBTA said that they were "deeply disappointed that this incident occurred and sincerely apologize to our riders who were on the train, as well as to our ridership as a whole."
"A preliminary inspection indicates a section of the sheet metal, or side panel, on the vehicle, appears to have come in contact with the third rail, igniting material below the car. We will be transparent with our findings and will provide updates as they become available," they wrote.
During Thursday's news conference, Poftak also expressed condolences.
"Obviously, this is a very frightening event and not the service that the MBTA wants to provide," Poftak remarked. "It is these types of incidents that we are working to prevent and avoid every day."
The train, put into service in 1980, was last inspected on June 23, Poftak said at a news conference, according to The New York Times.
Poftak remarked that it was unknown if heat played any role in the fire. "I don't want to engage in guess work," he said, according to the newspaper. "It will be something that we look at."