All five NY chopper crash passengers dead

A helicopter carrying six people crashed in New York City's East River killing all passengers, while the pilot escaped, police say.

Two of the five passengers died at the scene and three were taken to two area hospitals where they later died, a spokesman for the New York City Police spokesman confirmed on Monday.

The pilot freed himself and was rescued. He was treated and released from hospital in good condition, police said.

The Federal Aviation Administration said the Eurocopter AS350 went down near the northern end of Roosevelt Island around 7pm local time.

"It's a great tragedy," said New York Fire Commissioner Daniel Nigro at a press conference on Sunday. "It took a while for the divers to get these people out."

The passengers were tightly harnessed and the harnesses had to be cut and removed to free the passengers in the helicopter.

New York City Police Commissioner James O'Neill said the aircraft was registered to Liberty Helicopters, a sightseeing and charter service in New York, and was on a private charter photo shoot.

The US Coast Guard launched three boats to aid in the response, joining New York City emergency responders.

"It kind of hit sideways and just flipped over," Brianna Jesme, 22, an Upper East Side resident who witnessed the crash, told Reuters TV.

Video of the incident filmed by an onlooker and posted on Twitter showed a red helicopter descending toward the water at dusk, then landing with a large splash before tipping onto its right side, its tail lights still flashing.

Reuters could not immediately verify the authenticity of the footage.