A northbound Metro-North train ran over a mattress in the Bronx Thursday, sparking a fire that shorted out the third rail, according to the MTA.
Authorities say the fire, which is being investigated as a possible act of vandalism, started in the rear compartment of a train near the Tremont station just after noon.
The MTA said there were no injuries and the 750 passengers on the train were escorted onto the platform.
Firefighters were able to quickly put out the blaze.
There were 30 to 60 minute delays on the Metro-North's Harlem and New Haven lines for a few hours but normal service had resumed by 3 p.m. Thursday, officials said.