All five passengers have been killed after a helicopter crashed into New York City's East River.
Police say a sixth person, the pilot, freed himself and was rescued by a passing tugboat on Sunday night.
The helicopter was being chartered for a photo shoot when it went down near Gracie Mansion, the mayoral residence.
Video posted on Twitter shows a red helicopter land hard in the water and then flip on its side as its rotors struck the water.
Witnesses on a waterfront esplanade near where the aircraft went down said the helicopter was flying noisily, then suddenly dropped into the water and quickly submerged.
But the pilot appeared on the surface, holding onto a flotation device as a tugboat and then police boats approached.
"It's cold water. It was sinking really fast," Mary Lee, 66, told the New York Post. "By the time we got out here, we couldn't see it. It was underwater."
Celia Skyvaril, 23, told the Daily News that she could see a person on what looked like a yellow raft or float screaming and yelling for help.
News footage showed one victim being loaded into an ambulance while emergency workers gave him chest compressions.
A bystander, Susan Larkin, said that she went down to see rescue boats in the river and a police helicopter circling overhead, hovering low over the water.
"You could clearly see they were searching," she said.
A Federal Aviation Administration spokeswoman said the Eurocopter AS350 went down just after 7pm.
The aircraft was owned by Liberty Helicopters, a company that offers both private charters and sightseeing tours popular with tourists.