A 31-year-old man was found dead on the edge of the southbound Q train platform with severe trauma to his head and body, according to police.

Authorities said they first responded to a 911 call for an assault, when they discovered the man unresponsive.

Witnesses saw his body lying in the tracks bloodied and mangled.

It is unclear how exactly the assault led to the man’s death, but police did confirm some sort of dispute between him and someone else happened moments before.

Police said they had a person in custody for questioning Wednesday night, but that was no longer the case as of Thursday morning.