He was one of two teens who were walking along the water at East 105th Street and the FDR Drive in East Harlem.
They were apparently walking on a railing, when the boy fell into the water.
The NYPD and FDNY responded to the scene.
Authorities say the teen was under water for at least 20 minutes before he was pulled out.
Rescue crews worked to try to save him, after bringing him up from the water.
"We arrived in three and a half minutes," said FDNY Battalion Chief John Donnelly. "We had a diver in the water in ten minutes."
Despite their frantic efforts, the boy was pronounced dead a short time later at Metropolitan Hospital.
"I've never seen anything like that," said a witness, Carmen Vazquez. "And seeing a limp body like that, so young..it's hard."
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