A helicopter crashed into the East River off 34th Street at 3:22 p.m. on Tuesday, killing a woman passenger and injuring three other passengers, at least one of them critically, the authorities said. The pilot escaped unharmed.

The helicopter was “departing 34th Street and appeared to have some sort of trouble and tried to come back,” said Paul J. Browne, the head police spokesman.

The body of the woman was brought up around 4:50 p.m. by police divers.

Moments after the crash, televised coverage on WCBS-TV Channel 2 showed two men clinging to the inverted skids of the helicopter. A witness, Luis Reyes, said the men were yelling for help. “They were screaming ‘three more inside!’ ” Mr. Reyes said.

A man in a suit and a purple dress shirt was seen doing the backstroke toward the East 34th Street Heliport, and rescue divers were pulling another man in business clothes — possibly the pilot — ashore. Two female passengers were also pulled to safety.

Then the helicopter dropped 40 feet to the river’s muddy bottom, with the last passenger trapped inside.

The woman who died was 40 years old and lived in Sydney, Australia, Mr. Browne said. Her parents, who live in Portugal, were two of the survivors, he said. The other passenger, Mr. Browne said, was a friend of the woman who died and also lives in Sydney. None of their names were immediately released.

Jason Gregory, one of the officers who brought up the body of the woman passenger, said that the helicopter was under 40 feet of water, upside-down in the mud. “The visibility was about four feet,” Officer Gregory said. The woman lay unbuckled inside the helicopter, he said. “We removed the one female victim to the surface.” The helicopter went down about 50 yards from shore, said Lt. Larry Seras, a member of the police rescue unit that went into the water first. — ANDY NEWMAN

In a news conference at the crash site, Mayor Michael R. Bloomberg said that two of the passengers were British and lived in Portugal and the other two lived in Australia. “They apparently all knew each other and at least some of them knew the pilot,” he said. He said that the pilot, Mr. Dudley, escaped unharmed. — ANDY NEWMAN

Another witness, Jose Reyes — no relations to Luis Reyes — said the helicopter spun around laterally at least twice just before it went down, its nose jerking up and down. “It was completely out of control,” said Mr. Reyes, a doorman at a building nearby on First Avenue. The helicopter hit the river with an enormous splash that nearly touched the bottom of the overpass over the F.D.R. Drive, he said. — PATRICK WALL

The authorities identified the pilot as Paul Dudley, the director of Linden Airport in New Jersey. The site nycaviation.com reported that the helicopter is based in Linden and was formerly operated as a news chopper by KMOV-TV Channel 4 in St. Louis. Mr. Dudley was the pilot of a Cessna light plane that made an emergency landing in a Brooklyn park in 2006. In 2009, Mr. Dudley was interviewed in a New York Times article about navigating the crowded skies above the Hudson River.

Around 4:50 p.m. the missing woman was found underwater and brought to the surface by police divers, a city official said. She was dead. — AL BAKER

WCBS-TV Channel 2 and others are reporting that the last passenger has been pulled from the helicopter, but there are no reports on her condition.

Mr. Browne said that the missing person was a woman. He said helicopter was a Bell 206 – Jet Ranger and that the passengers might have been British but that he could not confirm that. Mr. Browne said that a roving police Emergency Service Unit happened to hear the call and respond. The officers “got out and saw that the pilot and three passengers in the water, and they jumped in and rescued them,” he said. — AL BAKER

The accident was reminiscent of one in February 1990 involving a similar type of helicopter at the same heliport. In that crash, a Bell 206 Jet Ranger lifted off from the 34th Street heliport at about 3 p.m. with five people aboard, then plunged into the East River. One passenger, a 14-year-old boy from Long Island, was critically injured. That crash was the third time in five years that a helicopter had plunged into the river near that heliport. Crashes in 1985 and May 1988 had each killed one passenger. In June 2005, two helicopters went down in the water off Manhattan in one week. One, a Sikorsky S76C, sank in the East River seconds after taking off from 34th Street. It was carrying six executives of a financial-services company who had flown up from their offices in Wilmington, Del., to negotiate the sale of their company to a New York bank. All of them escaped with minor injuries. — PATRICK MCGEEHAN

One witness, Carlos Acevedo, who was on the pier near the heliport with his girlfriend, said he believed the helicopter that crashed was trying to land, but that a second helicopter was on the helipad blocking its ability to do so. The one in the air began rising slightly, then it began spinning around and then went straight into the water, Mr. Acevedo said. “It spun around a few times and then went into the water,” said Mr. Acevedo, 40, who spoke in Spanish. “Then some employees from the heliport scrambled around and lowered ladders into the water. That’s when the police and firemen showed up.” He said the chopper went underwater quickly. “It sank fast,” he said. “In seconds.” — ROB HARRIS

Two injured women aged 45 to 55 were taken to Bellevue Hospital Center, fire officials said. The younger was in critical condition and the older one in serious condition, the authorities said. “One is in cardiac arrests and one is in respiratory arrest,” said James Long, a department spokesman. A man about 50 years old was in “serious condition” at New York University Langone Medical Center. A second man in his 50s, who Mr. Long said is the pilot, is still being treated at the location of the crash and is conscious, said Mr. Long. “Those we have dealt with so far are all adults,” said Mr. Long. Mr. Long said that the helicopter landed hard, according to reports. — AL BAKER

The New York Times Paul J. Browne, the Police Department’s chief spokesman, said the helicopter had five people on board when it crashed into the East River, off 34th Street. “The pilot and three passengers are out of the water,” said Mr. Browne. “And one is unaccounted for.” Mr. Browne declined to describe the conditions of those who were taken from the water. The age and gender of the missing person was not immediately known. Mr. Browne said that five New York Police Department boats were on scene and that N.Y.P.D. divers were in the water, searching. “The helicopter is submerged in an estimated 50 feet of water,” said Mr. Browne. He said the helicopter had attempted to take off moments before. “It was departing 34th Street and appeared to have some sort of trouble and tried to come back,” said Mr. Browne, who could not detail, immediately, the trouble the craft encountered. Then it crashed. He could not describe what type of helicopter was involved — but he stressed it was “not a tour company.” The Coast Guard has closed the East River to traffic for the time being.