"The smoke was orange coming off the train, it was still on fire at that point. The front car was billowing heavy smoke out of the windows and doors," said Jared Woodard, an employee of BGC Financial in New York, who was on the train travelling home to Chappaqua.
Hundreds of passengers from the eight-car train were taken to a rock-climbing gym for shelter, authorities said. The average number of passengers on the train is 650 on a line that carries commuters through affluent New York City suburbs such as Westchester County, one of the richest in the United States.
Media reports said the driver of the car got out briefly to try to push it off the tracks, then got back in before it was hit by the train. Officials did not say why the car was stalled on the tracks.
The train left Grand Central Terminal in midtown Manhattan at 5:44 pm and was headed north to Wassaic in southeast New York state.
Parts of the train line would stay closed on Wednesday morning, said the Metropolitan Transportation Authority (MTA), which was arranging for shuttle buses to fill the gap and warned of crowds and delays for thousands of commuters.
Westchester County is home to many bankers and corporate lawyers, boasts a median household income of roughly $82,000, and houses the headquarters of major companies, including IBM and PepsiCo Inc.