A helicopter plunged into the frigid waters of New York City’s East River on Sunday night, killing five of the six people on board, authorities said.

The red helicopter crashed into the river near Roosevelt Island, between Manhattan and Queens, at about 7 p.m., police said. Videos captured by witnesses show the helicopter descending quickly, capsizing and tilting onto its side, its rotor blades still spinning in the water.

The pilot managed to free himself and call out for help from a flotation device, witnesses told reporters on the scene. A fire boat took the pilot to shore, where an ambulance transported him to a hospital, New York Fire Department Commissioner Daniel A. Nigro said in a news conference, adding that the pilot is “okay.”

The five passengers on the helicopter were all “tightly harnessed,” so emergency fire and police responders had to cut the harnesses to remove them, Nigro said. Two of the passengers were pronounced dead in the initial hours after the crash, while three others remained in hospitals in critical condition. Early Monday morning, a spokesman with the New York Police Department confirmed to The Washington Post that all five passengers had died.

The helicopter was upside down and completely submerged when the response teams arrived, after authorities received dozens of 911 calls from witnesses, O’Neil said.

The helicopter, a Eurocopter AS350 was a private charter commissioned for a photo shoot, said James P. O’Neill, commissioner of the New York City Police Department. It is owned by Liberty Helicopters, a New Jersey-based company that claims to be the “largest and most experienced helicopter sightseeing and charter service in the Northeast,” according to its website. Providing sightseeing trips since 1990, the company advertises “unparalleled safety records.”

Fire and police teams worked in below-40 degree temperatures, and 50-foot deep water with 4-mile-per-hour currents to remove the passengers from the helicopter, Nigro said.

“It took a while for the divers to get these people out,” Nigro said. “They worked very quickly, as fast as they could.”

“It’s a great tragedy that we had occur here on an otherwise quiet, Sunday evening,” Nigro added.

The Federal Aviation Administration said it is investigating the crash. The National Transportation Safety Board is also investigating and said a team would be arriving by morning.

“For about a minute and a half no one came out of the water,” Brianna Jesme told a NY1 reporter. “Then we saw one guy climb onto the raft and he was yelling for help.”

Witness Celia Skvaril told the reporter she saw the man float all the way down the river on the raft, but did not see anyone else emerge from the water.

“It was a pretty hard hit and then it flipped over,” Skvaril, 23, told the New York Daily News. “We didn’t see the helicopter anymore and then a yellow raft popped up and again we didn’t see or hear anyone until we saw a person on top of the raft screaming and yelling for help and waving.”

Video footage on Twitter shows a man wrapped in a white blanket walking alongside emergency responders on East End Ave., near the Upper East Side, after the crash. Other videos show emergency responders performing CPR on a victim on a stretcher being loaded onto an ambulance.

Authorities had not yet released the names of the deceased early Monday morning. Travis Howard, a St. Louis resident, told The Post his family was panicking Sunday night because they had not yet heard from his 26-year-old brother-in-law who they believed may have been on the helicopter.

His brother-in-law, a video journalist who moved to New York City a few months ago, posted an Instagram story showing him riding in a helicopter with other people shortly before the crash occurred. In the video, Howard’s brother-in-law is seen smiling and laughing, with three people sitting behind him as the helicopter appears to be taking off. One of the men behind him flashes him a thumb’s up. The video captures a view of a river and a bridge, the sun setting in the distance.

At about midnight, Howard had tried contacting police and three different hospitals and had not yet determined whether his relative was among the victims. The man’s immediate family members had not been able to reach him all night, and had not heard anything from him since he posted his Instagram story. Howard did not know whether the helicopter trip was in any way related to his work as a video journalist.

“It’s just tough not being able to speak to anyone or not having any information,” Howard said. “It’s very much so a panic.”

Shortly after 2 a.m., Howard received a call back from the NYPD. His brother-in-law, police told him, was among the deceased. Authorities have not yet confirmed to the public that he was among the dead, and Howard asked that his brother-in-law’s name not yet be identified.

A number of plane and helicopter crashes over New York City’s East River and Hudson River have claimed lives in the last several years. In 2009, a tourist helicopter operated by the same company collided with a small, private plane over the Hudson River, sending both aircraft plunging into the water and killing nine people. A crash over the East River in October 2011 left three people dead. Two others survived.

And in 2009, of course, Capt. “Sully” Sullenberger glided his US Airways Charlotte-bound plane to safety in the icy waters of the Hudson River, expertly evacuating passengers and crew members. All 155 people on board survived the episode, which was depicted in the 2016 movie “Sully” starring Tom Hanks.

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