Police said Carlos Medina, of Manhattan, was found unresponsive in the pool at Canteen at Fire Island Pines just after 7:00 p.m. on Fourth of July.
He was rushed to the mainland and taken to the hospital in Bay Shore, where he was pronounced dead.
An autopsy will determine how he died.
Detectives are asking anyone with information on this incident to call the Homicide Squad at 631-852-6392 or Crime Stoppers at 1-800-220-TIPS. All calls will remain confidential.
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