A helicopter crashed on the roof of a rain-shrouded midtown Manhattan skyscraper Monday, killing the pilot and briefly triggering memories of 9/11, though it appeared to be an accident.

The crash near Times Square and Trump Tower shook the 750-foot (229-meter) AXA Equitable building, sparked a fire and forced office workers to flee on elevators and down stairs, witnesses and officials said.

The pilot was believed to be the only one aboard, and there were no other reports of injuries, authorities said.

It was not immediately clear what caused the crash, or why the Agusta A109E was flying in a driving downpour with low cloud cover and in the tightly controlled airspace of midtown Manhattan. A flight restriction in effect since President Donald Trump took office bans aircraft from flying below 3,000 feet (914 meters) within a 1-mile (1.6 km) radius of Trump Tower, which is less than a half-mile (0.8 kilometers) from the crash site.

The helicopter went down about 11 minutes after taking off from a heliport along the East River, a little more than a mile (1.6 km) away. Police Commissioner James O'Neill said it may have been returning to its home airport in Linden, New Jersey.

The 19-year-old helicopter was linked to a real estate company founded by Italian-born investor Daniele Bodini, according to Federal Aviation Administration records. The company referred an inquiry to a lawyer. A message was left with the attorney seeking comment.

Pedro Rodriguez, a pastry line cook at Le Bernardin, a well-known restaurant in the building, said workers got an announcement telling everyone to exit, and he later heard from people around him that there was a fire on the roof.

The evacuation was not chaotic, Rodriguez said, but he was rattled because he immediately thought of the Sept. 11 attacks.

"It's scary when something like this happens," he said.

The crash happened shortly before 2 p.m., when clouds obscured the roof of the building. Rescue vehicles swarmed to the scene a few blocks from Rockefeller Center.

"If you're a New Yorker, you have a level of PTSD, right, 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," Gov. Andrew Cuomo told reporters.

Videos posted by onlookers showed emergency vehicles in the street, but no obvious damage to the skyscraper. The fire department later tweeted a photo of the helicopter's wreckage that showed piles of burned debris on the roof.

Working for a bank on the building's seventh floor, Kendall Sawyer felt a shake — "jarring enough to notice," but workers weren't sure what it was, she said.

Then came an announcement that the situation was being looked into, and a few minutes later, an instruction to evacuate, without explanation, she said.

"It was a little bit crazy, a little bit scary" as workers walked down the stairs, she said.

A block south, lawyer Lance Koonce heard a loud sound he thought could be a low-flying helicopter. From his 21st-story window, he looked up and saw smoke.

"I couldn't tell if the smoke preceded the helicopter coming over, or if it was from the helicopter crashing into the building," he said.

Trump tweeted from Washington that he had been briefed on the crash. Cuomo's office said the president and governor had spoken.

The National Transportation Safety Board was sending an investigator.

The city currently allows helicopters to take off and land from three heliports, one each on the East and West sides and in downtown Manhattan. All of the facilities border rivers.

It was once more common for helicopters to take off from private Manhattan rooftops, the most famous of which was on the tower then known as the Pan Am building. In 1977, four people waiting on the roof were killed when a helicopter toppled over and a rotor blade broke off and hit them. A fifth person, a pedestrian, was killed by falling debris.

That spurred a push to close down private helipads.

Still, the city has seen a string of helicopter accidents since. The most recent was just last month, when a chopper crash landed in the Hudson River near a busy Manhattan heliport. The pilot escaped mostly unscathed.

Five people died when a sightseeing helicopter crashed into the East River last year. Three people died in another crash into the same river in 2011. Back in 2009, a sightseeing helicopter collided with a small plane and killed nine people not far from the scene of Monday's mishap.

In 2006, New York Yankees pitcher Corey Lidle's single-engine plane slammed into the 20th floor of a building on Manhattan's Upper East Side, killing Lidle and his flight instructor. It was not clear which one was piloting the plane.

The National Transportation Safety Board concluded the pilot misjudged a narrow U-turn before veering into the building.

Monday's crash prompted some New York lawmakers, including Reps. Carolyn Maloney and Nydia Velazquez, to propose banning certain "non-essential" helicopter flights over Manhattan. And it brought a reflection from Rep. Sean Patrick Maloney, a fellow Democrat who said he formerly worked in the building.

"Today's crash hits home," he said.

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Associated Press writers Michael R. Sisak, Deepti Hajela, Tom McElroy, Kiley Armstrong and Jennifer Peltz in New York and Michael Balsamo in Washington contributed to this report.