Three British tourists have been taken to hospital after a helicopter crash in New York which left a fourth person dead.
The four passengers were pulled out of the East River after the accident happened at 3.22pm local time.
Two of those injured, both women, are in a critical condition. A man is in a stable condition in hospital. All are believed to be from England.
NYPD spokesman John Grimpel said the names and ages of those involved are not yet known.
A spokesman for the New York Fire Department said: "We got the call at 3.22pm for us to respond to a helicopter crash.
"We did, and four people were pulled from out of the water.
"Two females are in a critical condition. One had suffered a cardiac arrest and one a respiratory arrest.
"They were both taken to Bellevue Hospital."
The injured man was taken to NYU Hospital.
A Foreign and Commonwealth Office spokesman said: "We are urgently investigating reports."
The dead passenger is a women, NYPD said.
Dan Sweeney, manager at the nearby Water Club restaurant, told US news outlet NBC NewYork that the helicopter appeared to be in the process of landing when it crashed.
"It went down pretty fast, you could see the splash, you could see the top of it and it just disappeared," he said.
"It looked like it was trying to land at the heliport and missed the landing."
Police said it had taken off in cloudy conditions from the 34th Street and East River Heliport but could not confirm whether it was attempting to land.
Detective Martin Speechley told Sky News there were "multiple" difficulties with the search and recovery operation.
He said: "The biggest one to overcome is that these rivers aren't very clear. You really can't see more than a foot in front of your face.
"Most of the rescue effort would have been done by touch."
He said the emergency services were "fairly confident" they had retrieved all the people from the water, but rescuers were still in the river.
He added: "At the moment, of course, we're going to have one or two divers in there.
"Following confirmation we've got everybody out of the water, then we'll be concentrating on getting the helicopter out of the water."
A spokesman for the British Embassy in Washington said: "We are urgently investigating with the authorities in New York."
According to US reports the pilot was Paul Dudley, director of Linden Airport in New Jersey.
Mr Dudley piloted a Cessna light plane that made an emergency landing in a Brooklyn park in November 2006 after an engine failure.
Police said the private helicopter involved in the crash was manufactured by Bell Helicopter.
Witnesses said it was sputtering and appeared to be in mechanical distress before coming down in the river. A dozen boats and divers took part in a rescue effort before passengers were pulled from the water.
Joy Garnett and her husband were waiting to take the East River ferry to Brooklyn when they heard the blades of a helicopter and saw it start to take off from the nearby helipad. It then did a "funny curlicue", Mrs Garnett said.
She added: "I thought, 'Is that some daredevil move?'. But it was obviously out of control.
"The body spun around at least two or three times, and then it went down."
The helicopter flipped over once it was in the water, with onlookers throwing life jackets and buoys down to those inside.
Witness Carlos Acevedo said: "It sank fast. In seconds. Like the water was sucking it in."