03/11/2013 12:57 pm ET Updated May 11, 2013

BART Elevator Death: Man Fatally Crushed In San Francisco Subway Shaft

A man was crushed to death in the shaft of a BART elevator at San Francisco's Montgomery station Sunday night, according to transportation officials.

A passenger was taking the elevator up one level when he heard "a crunching sound and a man yelp before the elevator stopped," BART Police Lieutenant John Conneely said. The elevator car then stopped and became stuck.

The passenger called the police and fire departments for help. After he was successfully released from the elevator, authorities searched the shaft and found a man's body, which was immediately pronounced dead.

Conneely said the man may have been sleeping atop the elevator, but it remains unknown as to how he wound up in the shaft or how long he had been inside it. Personal belongings were found on top of the elevator car, and it is uncertain whether they belonged to the man.

No BART delays were reported during the ordeal. The deceased man's identity has not been released.