‘Mechanical problem’ on Red Line sent smoke into station and snarled some people’s Friday commute

A Red Line train arrived at the MBTA Park Street station in Boston on March 10, 2023.Craig F. Walker/Globe Staff

A mechanical problem on a Red Line train Friday morning disrupted service for about 2½ hours, causing another hectic commute for subway riders who had to shift onto shuttle buses to reach their destinations.

The train broke down and began giving off smoke at about 9 a.m. inside Central Square station in Cambridge, according to the MBTA. Acting Cambridge Fire Chief Tom Cahill said no fire erupted, but smoke from an overheated motor filled the station.

The smoke cleared once the T cut power to the motor, he said.

Firefighters helped to evacuate passengers from the station, but no one required medical attention, Cahill said.

Red Line T riders pack a Central Station platform after a train is taken out of service because of a mechanical issue.Nicole Merullo

The MBTA suspended Red Line service between Harvard station and Park Street in Boston and moved riders onto shuttle buses, according to Joe Pesaturo, a T spokesman. Regular subway service resumed at about 11:30 a.m., he said.

The cause of the mechanical problem is under investigation, Pesaturo said. The train that broke down is part of a fleet of Red Line cars built between 1987 and 1989, the agency said.

The train left Braintree station at 6:53 a.m. on its first trip of the day, Pesaturo said.

Elise Thomson, 28, got on the Red Line at Porter station and immediately noticed an acrid smell, similar to burning rubber, she said. She also heard a loud thrumming noise as the car inched along the tracks.

“The train was getting slower and slower as we went down the Red Line,” Thomson, a scientist, said in a phone interview. “When we got to Central, they evacuated us, but the whole station was filled with smoke.”

Inside the station, people began putting on masks. The crowd stood in the smoke for several minutes before they were eventually led outside by MBTA staff, Thomson said. She waited for about 15 minutes to catch a shuttle bus to go to work.

“I was just like, honestly, whatever,” she said. “It’s just another day for the MBTA,” Thomson said.

Lee Nave Jr., 33, said the smoke was unbearable inside Central station. He had boarded the Red Line just one stop before passengers were forced to evacuate.

Passengers at Central station cover their mouths as smoke fills the train platform.Nicole Merullo

“The smell was horrible,” Nave said. “The station was just filled with it. People were coughing and everything.”

State Representative Mike Connolly, a Cambridge Democrat, said he walked to the T station after he saw a tweet reporting a large number of fire engines in the neighborhood.

Commuters took the setback in stride, he said in a phone interview.

“It’s just another day of the MBTA disaster,” said Connolly, who lives near the station. “We have to continue to demand the transit system we deserve.”

On social media, some passengers described being evacuated from the train.

“Day is off to a banner start with my MBTA red line train filling up with smoke and being decommissioned at Central station, which was consequently also filled with smoke,” one passenger tweeted.

Riders posted photos as they filed out of the smoky station. The disabled car sat with its lights off and doors open. Others social media users captured crowds of people waiting outside for shuttle buses to arrive.

John R. Ellement of the Globe staff contributed to this report.