Earlier, New York Police Commissioner Jessica Tisch said the identities of the victims will not be released until the families are notified.
Video footage of the incident shows the helicopter falling out of the sky upside down and then splashing into the Hudson River.
Officials said the helicopter lost control soon after turning at the George Washington Bridge to move along the New Jersey shoreline.
The helicopter was operated by New York Helicopters and took off from the Downtown Skyport on the lower side of Manhattan at 14:59 local time (19:59 BST).
Michael Roth, the CEO of New York Helicopter Charter Inc, told CNN he was “devastated”.
“I’m a father, a grandfather and my wife hasn’t stopped crying since this afternoon,” he said. When asked about the maintenance of the helicopter, Mr Roth said, “It’s my director of maintenance who deals with that.”
Eyewitnesses who saw the crash told CBS News, the BBC’s US news partner, that they saw parts of the helicopter fall from the sky.
“I looked outside my window. I saw a few people running towards the water, and some people were acting pretty normal. So I was like oh, it might not be anything. Then I started to hear all the sirens come outside,” Jersey City resident Jenn Lynk said.
Another Jersey City resident, Ipsitaa Banigrhi, told CBS the crash sounded like thunder.
“I saw, like, black particles flying,” she said. “Again, I thought maybe it’s just like, dust, or birds, and then we heard all the emergency vehicles and sirens go by, and I think that’s when it was like, OK, what’s happening.”
This is not the first deadly tourist helicopter crash in New York City. In 2018, another tourist helicopter crashed into the East River and all five passengers drowned. Only the pilot survived.
