Metro

Subway surfer almost killed in Park Slope

A Brooklyn teen smashed his head on a metal beam and lost an eye while subway-surfing early Tuesday with his pals — just days after a drug-addled man died doing the same thing in Manhattan, law-enforcement sources said.

A train operator going toward Manhattan spotted Isa Islam, 17, atop the Brooklyn-bound F train heading for the Fourth Avenue-Ninth Street station in Park Slope with three others and radioed authorities at 2:20 a.m., sources said.

The motorman on Islam’s train stopped as it pulled into the station, and rescuers found the teen bloodied on top after power was cut, sources said. The teens he was with took off.

Islam lost an eye, and is fighting for his life at Lutheran Medical Center, where his family visited him later in the day, according to neighbors.

Police identified him through his cellphone, sources added.

A barefoot homeless man was killed last Wednesday after he got on top of a downtown 6 train as it entered the 96th Street station and was hit by a beam.