A helicopter has crashed onto a building on Manhattan’s 7th Avenue, the Fire Department in New York has said.
The White House says US President Donald Trump has been briefed, and will continue to monitor the situation.
The crash happened close to the Empire State Building and Times Square.
New York Governor Andrew Cuomo, who is at the scene, said a fire started when the crash happened and the building shook.
He said he believed the helicopter had tried to conduct a forced emergency landing.
The fire department said in a tweet that one death had been reported.
People inside the building were evacuated after the incident, with Mr Cuomo saying no injuries were reported from anyone inside.
He added that he understood that the crash would prompt people to think of 9/11, but he offered reassurances.
Emergency services have blocked the streets with dozens of fire engines and police cars.
The weather in New York is currently wet and cloudy, with one witness in an adjacent building describing the crash site as “very foggy”.
Sky News correspondent Hannah Thomas-Peter said: “There’s very, very limited visibility – it’s really raining hard.”
An early report from the fire department said one person had been injured.
In a tweet, the Federal Aviation Administration said it was “gathering information” on the incident and would issue a statement shortly.