A crowded Metro-North Railroad train passing through Westchester County at the height of the evening rush on Tuesday slammed into a sport-utility vehicle on the tracks at a crossing, creating a fiery crash and explosion that killed seven people, injured a dozen and forced the evacuation of hundreds. It was the deadliest crash in the railroad’s history.

Passengers were temporarily stranded after evacuating the train, as its front car continued to release billowing smoke into the cold night air. Service was suspended on the Harlem line on Tuesday night as firefighters responded to the smoking car and officials said they were investigating what had led to the crash.

The train hit the S.U.V., a black Jeep Cherokee, in the crossing at Commerce Street in Valhalla, N.Y., around 6:30 p.m., officials with the Metropolitan Transportation Authority said. The driver of the vehicle and six people on the train were killed, Gov. Andrew M. Cuomo said after touring the scene late Tuesday.