THE BRONX - A man in a green jacket allegedly beat another man at East 233rd Street and White Plains Road Friday.

The victim later died, but police haven't said definitively what caused his death.

Witnesses say the victim bumped into the suspect and the two got into an argument before the assault. Surveillance video of the scene shows only their feet during the scuffle.

Cellphone video from a witness shows emergency responders performing CPR on the victim, who is lying on the sidewalk.

According to witnesses, as the victim struggled to breathe on the ground, the suspect walked away "very casually."