The helicopter that crashed on top of a Manhattan building was only in the air ...

The helicopter that crashed into a Manhattan building was only in the air for 11 minutes, officials said.

"At approximately 1:32 this afternoon, the helicopter took off at the 34th Street heliport and about 11 minutes later crashed across the street from where we are now," Police Commissioner James O'Neill said at a news conference.

O'Neill said the first 911 calls came in at 1:43 p.m. ET and reported a crash and a fire on top of a 54-story office building on 7th Avenue.

Officials said several agencies are working together to figure out why the helicopter was in the area, and what went wrong.

"Right now, the FBI are working with the FAA and the NTSB to gather additional info on the pilot, we believe we've tentatively identified the aircraft, the flight path, and its owner," O'Neill said.

New York authorities have preliminarily identified the pilot who died in Monday’s helicopter crash.

“We have him preliminarily identified, but it’s not confirmed yet. Plus we’re looking out for his family too,” NYPD Commissioner James O’Neill said in a news conference.

Asked if the pilot made a stress call from the helicopter, O'Neill said, "That’s part of the investigation – to see if there was any contact made with air traffic control.”

The building involved in the helicopter crash did not have a landing pad, New York City Mayor Bill de Blasio told CNN.

"Helicopters have not been landing on buildings in Manhattan for decades," he said. "There was a horrible crash in what was the Pan Am building some years ago and it was banned after that. And in fact, a helicopter should not in this area of Manhattan without the approve of LaGuardia Airport tower."

De Blasio added that the helicopter shouldn't have been in the area especially because of Trump Tower.

"But something like this should have been authorized. We don't have any indication it was, but we're still investigating to confirm that," he said.

The mayor said the aircraft was flown by a "commercial pilot."

"This is someone who's been doing this work for a while. Apparently was an executive helicopter used to ferry around executives," de Blasio said.

The building where a helicopter crashed this afternoon is owned by CALPERS, the California Public Employees’ Retirement System, according to a tweet by the agency.

"We are aware of the helicopter crash in New York City involving a building in our real estate portfolio," CALPERS tweeted.

According to the CALPERS website, they manage the largest public pension fund in the US.

New York City Mayor Bill de Blasio said there is no indication that today's helicopter crash is terror related.

“There is no indication at this time that this was an act of terror and there is no ongoing threat to New York City," he said.

Later he again stressed: "We have no indication that there was any terror nexus here."

Mayor Bill de Blasio said there were no other injuries to anyone in the building and on the ground.

"And I want to just say, thank God for that," he said. "This could have been a much worse incident. And thank God no other people were injured in this absolutely shocking, stunning incident."

The FAA has described the helicopter involved in a hard landing on top of a Manhattan building Monday as an Agusta A109E.

Here's what we know about this model:

The model referenced in the FAA statement was described in 2013 by the company: 

"The AW109 Power is a single-pilot IFR certified helicopter with a maximum cruise speed of 154 knots (285 km/h). The aircraft’s engines are controlled by a Full Authority Digital Engine Control (FADEC) system. A digital glass cockpit with six liquid crystal instrument displays provides the aircrew with flight, systems and mission data."  

IFR, or instrument flight rules, means the helicopter can fly in lower-visibility situations, but the pilot must also be trained to fly in those conditions.