An MTA cleaner died after falling on the trackbed early Thursday morning in the Bronx, according to the NYPD.

The 40-year-old man attempted to cross the tracks and then fell down at the MTA's 239th Street Yard & Maintenance Shop near Furman Avenue, the police department said in a release Thursday morning.

A law enforcement source says the worker may have come in contact with the third rail when he fell, but the Medical Examiner will determine the exact cause of death.

The department said emergency medical personnel pronounced the man dead at the train yard after officers found him unconscious around 5 a.m. on Thursday.

"We are devastated to learn early this morning of the death of a car cleaner at the 239th Street maintenance yard," NYC Transit Interim President Sarah Feinberg said in a statement. "A full investigation is underway to determine the cause. Our hearts go out to the cleaner's family and co-workers at this tragic time."

The worker's identity has not yet been released.