A young man pulled nearly lifeless from the waters just off the Coney Island boardwalk died at the hospital Monday morning, cops said.

The unidentified man – believed to be in his 30s – was unconscious and unresponsive when cops responded to a 911 call around 7:30 a.m. and found him floating in the Atlantic on the east side of the iconic Brooklyn beach, police said. 

A witness told police he’d been in the water for a “period of time,” sources said. 

The man, who was initially listed in critical condition, was pulled from the waterway and rushed to Coney Island Hospital, where he died, cops said. 

His identity was not yet known Tuesday, and it was unclear why he had been in the water.