NEW YORK (CBSNewYork) — Another unprovoked attack on a train was caught on camera this week.

A Bronx man is facing charges after he allegedly assaulted a passenger.

It’s still unclear what led to the incident, but police say a 62-year-old retired postal worker with Alzheimer’s disease was randomly attacked as he rode the F train downtown Thursday morning.

The victim, who doesn’t want to be identified, can’t understand why he was singled out.

“I sit there, and somebody hurt me, hurt my head,” he told CBS2’s Valerie Castro.

The assault left him with a gash in the back of his head and other injuries. Most of the incident was captured on cellphone video. More at CBS NY