NEW YORK — A 39-year-old man was killed Tuesday night in midtown Manhattan after a piece of his clothing or the strap of his bag apparently became caught on a subway train that dragged him into a tunnel, the authorities said.

Witnesses told the police that the man, whose name was not immediately released, had been walking on the yellow caution line along the edge of a platform at the Grand Central Terminal subway station around 7:20 p.m. when the clothing or strap somehow became ensnared on some part of a train that pulled away.

Surveillance-camera video from inside the station shows the man walking down the stairs onto the platform, and his body is later seen being thrown against a staircase and pulled into the tunnel, according to a law enforcement official.

The man’s body struck an electrical box near the entrance to the tunnel and set off a flash that caught the attention of the train operators and forced them to stop the train, the official said.

By the time the police arrived, the man was “unconscious and unresponsive with severe trauma to the body” the New York Police Department said in a statement. When paramedics arrived, the man was pronounced dead, the statement added.

In various tweets, the Metropolitan Transportation Authority confirmed the fatality and warned of significant delays, but an agency spokesman would not provide details about the episode late Tuesday. Instead, the MTA directed questions to the police.

This article originally appeared in The New York Times.