THE BRONX - Passengers were evacuated from a Metro-North train that caught fire on the Harlem line today.

Authorities say a mattress got caught under one of the cars and started a fire. Firefighters say its metal springs somehow caused sparks, which then torched the outside of the train.

Officials say the fire did not take long to put out.

About 750 passengers were on the train at the time of the incident. Emergency officials say everyone got off the train safely, and no one was injured.

MTA police are investigating the incident as a possible act of vandalism.

For Chopper 12 footage from above the scene, watch the clip to the left or click News 12 Extra on Optimum TV channel 612.