A man lit a sleeping homeless woman on fire in a Brooklyn subway car, then apparently watched calmly as she burned to death early Sunday, cops and sources said.

A person of interest has been taken into custody in connection with a woman who was set on fire and died Sunday morning on a subway train in Brooklyn, police said.Around 7:30 a.m., the woman and the suspect were both riding the "F" train to the end of the line at the Stillwell Avenue Subway station in Coney Island.

The "person of interest" was taken into custody hours after the attack while riding another train, according to NYPD Transit Chief Joseph Gulotta.