Emergency vehicles fill the street at the scene after a helicopter crashed atop a building in Times Square. Reuters

A helicopter crash-landed on top of a high-rise in midtown Manhattan on Monday, starting a fire and leaving one person dead as the entire building shook from the impact.

"There was a Helicopter hard landing on the roof of 787 7th Avenue in Midtown Manhattan," the New York Police Department tweeted as emergency services flooded the area.

"The fire has been extinguished, and members continue to operate in response to fuel leaking from the Helicopter. There is currently one fatality reported," tweeted the city's fire department.

President Donald Trump said he had been kept informed of the situation.

"I have been briefed on the Helicopter crash in New York City. Phenomenal job by our GREAT First Responders who are currently on the scene. THANK YOU for all you do 24/7/365! The Trump Administration stands ready should you need anything at all," Trump tweeted.

Speaking at the scene, New York Governor Andrew Cuomo told reporters there had been "casualties" on board the Helicopter -- suggesting the pilot was the person killed -- and that a fire briefly broke out, but that no one in the building had been hurt.

"The preliminary information is that there was a Helicopter that made a forced landing, emergency landing, or landed on the roof of the building for one reason or another," Cuomo said.

'Whole building' shifted

"People who were in the building said they felt the building shake," the governor added.

That was confirmed by Nathan Hutton, who works in the building on the 29th floor.

"We felt the whole building shift. We thought it was an earthquake or something like that. Something small like that. Then two minutes after, the alarms went off and then security came in: 'Everybody just grab your bag and walk out the door now!'" Hutton told AFP.

He said there was no panic, but going down the stairs "was scary because everybody from all the floors" was descending "all at the same time" -- a process that took half an hour.

"There was no shouting but a little nervousness, with the occasional, 'C'mon, move!" he added.

The city fire department urged people to avoid the area.

Five people died after a Helicopter plunged into Manhattan's east river near the upscale Upper East Side neighborhood in March 2018.

The chopper, which was owned by tourism group Liberty, was carrying six people including the pilot, who managed to free himself. The other five did not.

That crash led US aviation authorities to review regulations for so-called "doors off" flights, which provide passengers with a more direct view of the skyline than flights with the aircraft's doors shut.

Agence France-Presse