Man watching woman burn to death after setting her on fire

A man allegedly set a sleeping passenger on fire in a Coney Island subway train just before Christmas.

In a disturbing video, he is seen watching the flames engulf the woman who stood by the open door of the train.

A transit officer passed by but did not intervene.

The suspect, described as about 5'6" and 150 pounds, was last seen in a gray hoodie and dark knit hat.

Authorities are offering a $10,000 reward for information leading to his arrest.

Investigators believe he tossed a match on the woman while sitting across from her.

The victim was pronounced dead at the scene.

Liquor bottles were found near her, but their role in the incident is unclear.