A man sitting on the tracks of an elevated subway line in the Bronx was decapitated when a train slammed into him on Wednesday night, police and sources said.

The unidentified man was on tracks at the Castle Hill subway station when he was struck by a northbound 6 train at about 10:40 p.m., according to police.

His head fell down from the elevated tracks and landed on a sidewalk, police sources said, while his body remained on the tracks.

He died on scene.