NEW YORK (CBSNewYork) — A helicopter crashed on top of a building in Midtown on Monday afternoon.

It happened at around 1:43 p.m., according to FDNY Commissioner Daniel Nigro.

The helicopter was flying in restricted air space and in rain and fog when it crashed.

PHOTOS: Midtown Helicopter Crash

More than 100 emergency responders rushed to the scene at 787 Seventh Ave. between 51st and 52nd Streets. The building is 54 stories tall.

The pilot, identified as Tim McCormack, was killed. The East Clinton, New York, Volunteer Fire Department said he served as chief there for 10 years. Before joining the East Clinton VFD, he was a member of the LaGrange Fire Department. With 15 years of experience flying helicopters and single-engine airplanes, he was certified as a flight instructor last year, according to Federal Aviation Administration records.

McCormack radioed before the crash that he was in trouble, sources told CBS2. Paul Dudley, the airport manager in Linden, N.J., where the helicopter flew out of, said, “McCormack is an experienced pilot and very well respected in the aircraft community,” adding he worked for an executive and was flying his helicopter at the time of the crash.

Dudley said he assumes that there was a mechanical or weather-related issue and that McCormack was trying to land on top of the building to spare the people on the ground, CBS2’s Lisa Rozner reported.

There is no helipad on top of the building’s roof.

The FAA said the aircraft was an Agusta A109E helicopter and the NTSB will investigate the cause of crash. FAA air traffic controllers “did not handle the flight.” The helicopter was registered to American Continental Properties, LLC.

That model helicopter, which is used for executive travel, was flying in a restricted flight area when it crashed. Mayor Bill de Blasio said officials were investigating whether or not the chopper had received approval from flight controllers to go into the restricted zone.

The building was evacuated.

“There was a shake and then a noise and then we just evacuated,” one man said. “That was about it. We just heard the ground shake, like it was an earthquake and then we went back to business. Then we got the notice to evacuate.”

“You could smell smoke. Not heavy smoke, but the smell of what I describe — burnt construction material started to come downstairs,” another man said.

“We had a very strange, very troubling incident this afternoon here in Manhattan,” Mayor de Blasio said.

De Blasio emphasized that “there is no indication at this time that this was an act of terror and there is no ongoing threat to New York City based on all the information that we have right now.”

WEB EXTRA: Mayor de Blasio, Officials Discuss Midtown Helicopter Crash:

“We do not know the cause of this incident,” de Blasio said. “This could’ve been a much worse incident, and thank God that no other people were injured in this absolutely shocking, stunning incident.”

De Blasio praised the “extraordinary effort” of the first responders.

Nigro said firefighters were on the scene of the crash about four minutes after receiving the 911 call of the crash. They deployed special hoses and pumps to get water from over 700 feet below to fight the fire.

“We were able to put water on the fire quite quickly. Unfortunately, we did find a victim with the helicopter, who, as the mayor stated, we presume is the pilot,” Nigro said.

Images from the scene of today’s helicopter crash at 787 7th Ave. in Manhattan. #FDNY members remain on scene. There is one fatality reported. pic.twitter.com/7qyyJWrMsw — FDNY (@FDNY) June 10, 2019

“What we know is that at approximately 1:32 this afternoon, the helicopter took off from the 34th Street heliport and about 11 minutes later crashed on the roof,” Police Commissioner James O’Neill said. That heliport is located on Manhattan’s East Side. Officials believe – but have not confirmed – the helicopter may have been attempting to return to its home base in Linden, New Jersey, which is why it may have been crossing Manhattan.

O’Neill said he was “not sure” yet why the helicopter was flying in wet and foggy weather.

Gov. Andrew Cuomo, who happened to be at an event nearby and got to the scene quickly, said that a helicopter made a “forced” or “emergency” landing on top of the building. Officials later described the incident as a “hard landing” at a high rate of speed.

WEB EXTRA: Gov. Cuomo On Midtown Helicopter Crash:

“The preliminary information is that there was a helicopter that made a forced landing, an emergency landing or landed on the roof of the building for one reason or another. There was a fire that happened when the helicopter hit the roof. People who were in the building said they felt the building shake. The fire department believes the fire is under control. There may have been casualties involved in people in the helicopter,” Cuomo said. “We don’t know what caused the helicopter to land on top of the building but people in the building itself, nobody has been hurt.”

Evacuation in Midtown West. 51st Street and 6th Ave near Radio City Music Hall and Rockefeller Centre. We felt a jolt in our building and shortly after got the instruction to evacuate. #NYC #Evacuation #Midtown pic.twitter.com/lH2YwilqqJ — Javanni. (@JavanniWaugh) June 10, 2019

The damage was primarily contained to the building’s roof. In the midst of the chaos and confusion, Nicholas Estevez found a sharp piece of debris in the rain on the street below, CBS2’s Ali Bauman reported.

“I saw people running like crazy out of the building and people running everywhere,” he said.

“If you’re a New Yorker you have a level of PTSD from 9/11 and I remember that morning all too well. So as soon as you hear an aircraft hit a building, I think my mind goes where every New Yorker’s mind goes,” Cuomo said.

MORE: New Yorkers’ 9/11 “PTSD” Tested By Skyscraper Chopper Crash

Crosstown traffic now OPEN on ALL AVENUES except 50-52 streets. Northbound traffic on 6th Avenue from 34th to 57th streets has also RE-OPENED to traffic. Follow @NYPDTransport for more. https://t.co/x6h1RoSvBh — NYPD NEWS (@NYPDnews) June 10, 2019

West 50th Street-West 52nd Street between Sixth and Seventh Avenues was closed to vehicles and pedestrians, the NYPD said. Other streets near the crash site were closed but later reopened.

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. — Donald J. Trump (@realDonaldTrump) June 10, 2019

President Donald Trump tweeted praise for first responders, saying they did “phenomenal job,” adding “The Trump Administration stands ready should you need anything at all.”