A helicopter has plunged into a river in New York City, killing a woman and critically injuring two other people.Witnesses described how the privately owned Bell 206 aircraft spun out of control after take-off and fell into the East River near 34th Street in midtown Manhattan.New York Mayor Michael Bloomberg told reporters it is thought the helicopter was upside down when it crashed.He said it was not clear what caused the crash.Aboard the helicopter were a pilot and four passengers - a husband and wife, both British citizens, the wife\'s daughter, who is also British and died at the scene, and the daughter\'s Australian friend.The 40-year-old victim was recovered by rescue workers and pronounced dead at the scene.She was trapped inside the back of the chopper as it sank about 50 feet (15.2m) below the surface of the water, police said.As rescue workers pulled the helicopter wreckage out of the water, witnesses said it appeared to be outwardly intact.The aircraft was lowered by crane on to a recovery boat and will be taken to the Floyd Bennett Field in Brooklyn.At least seven boats joined the rescue effort earlierWitnesses described a man in the water diving down and coming back up, possibly in an attempt to free a trapped passenger.But police divers recovered the body of the dead woman about an hour after the aircraft went down at 15:22 (19:22 GMT).The pilot - named in US media as Paul Dudley - was able to make his own way to the river bank and remained at the scene.Two women - one of whom suffered cardiac arrest - and a male passenger were admitted to hospitals.Sunhe Dudley, the pilot\'s wife, said to the Associated Press news agency: \"These were actually very dear friends of ours that were in the helicopter.\"Weather conditions were clear with visibility of up to 10 miles (16km) and wind gusts at up to 20mph, according to the LaGuardia airport weather station.Dan Sweeney, manager of nearby restaurant, told US news outlet NBC New York that the helicopter appeared to be landing when it crashed.\"It looked like it was trying to land at the heliport and missed the landing,\" he said.Joy Garnett, a witness on a nearby dock, told the Associated Press that the aircraft had risen about 25ft (8m) off the ground, before spinning two or three times and dropping into the water.The helicopter flipped over, its blades sticking up out of the water, and was \"obviously out of control\", she said.Mayor Bloomberg said \"a tragedy like this just breaks your heart\", adding that the passengers had come \"to see the best of our city\".A spokesman for the National Transportation Safety Board said the pilot was being interviewed as part of the investigation into the crash.The US Coast Guard said the East River had been closed to commercial traffic.