NEW YORK (CBSNewYork/AP) — An investigation was underway Sunday after a fire at Trump Tower left one man dead and sent six firefighters to the hospital.

The man who died was found inside an apartment on the 50th floor of the Manhattan skyscraper after flames broke out Saturday afternoon.

Cory Rutledge was at work when he took video of what he describes as a chaotic scene.

“I just saw the FDNY and the fire trucks,” he told CBS2’s Jenna DeAngelis. “It was just massive. There were lights everywhere!”

Heavy flames and thick smoke shot out of the 5th Avenue high rise.

“I heard a big bang and the debris falling on the glass roof,” witness Will Hammonds said.

“There was noise and then a funny smell and Michael Cohen, who is Trump’s lawyer, texted me ‘are you in the building?’ And I texted him back, ‘Yeah.’ And he said ‘you should get out. There’s a fire.’ So I had to walk down all these flights,” resident Dennis Shields told CBS2’s Hazel Sanchez.

Flames shoot out of Trump Tower on April 7, 2018. (Photo: Citizen App)

The call came in just before 6 p.m. Saturday and within minutes about 200 firefighters and EMS workers arrived on scene.

“Units made their way up to the 50th floor,” FDNY Commissioner Daniel Nigro said. “The apartment was virtually entirely on fire. They pushed in heroically. They were knocking down the apartment. They found one occupant.”

The victim was identified as 67-year-old Todd Brassner. He was rushed to Mount Sinai West Hospital where he was pronounced dead.

Brassner was an art collector who spent time with Andy Warhol but later fell on harder financial times. Warhol made several references to spending time with Brassner in his posthumously published diaries. He also signed at least one print to him.

Jodi Stuart told CBS2’s Sanchez she was Brassner’s dear friend for more than 40 years.

“In that absolute second my entire body emptied out. It’s like I had nothing inside me. I just couldn’t believe it,” Stuart said. “Todd was his sidekick of Andy’s. And Andy embraced Todd. And Todd gave Andy great advice. And then to become the sellers of Andy’s art was amazing.”

Stuart said later in life Brassner became more of a recluse, and faded away from the public eye. But he never shied away from the friendships he cherished most.

“Todd was just the most passionate, creative, fun, loving, generous, generous to a fault, human being,” Stuart said.

Property records show Brassner had bought the apartment in 1996. He had filed for bankruptcy in recent years.

Half a dozen firefighters also sustained minor injuries in the blaze.

Fire officials say the Trump family wasn’t home when the fire broke out. The president took to Twitter on Saturday evening to thank the FDNY.

Asked if Trump Tower is indeed a well-built building, Nigro said, “It’s a well-built building. The upper floors, the residence floors, are not sprinklered.”

Fire sprinklers were not required in New York City high-rises when Trump Tower was completed in 1983. Subsequent updates to the building code required commercial skyscrapers to install the sprinklers retroactively, but owners of older residential high-rises are not required to install sprinklers unless the building undergoes major renovations.

Some fire-safety advocates pushed for a requirement that older apartment buildings be retrofitted with sprinklers when New York City passed a law requiring them in new residential high-rises in 1999, but officials in the administration of then-mayor Rudy Giuliani said that would be too expensive.

“They did their best and I think they did a terrific job,” Rutledge said. “I’m happy with the security and the way things were handled. They were very on top of it.”

The Department of Buildings issued vacate orders Sunday to apartments on the 50th floor where the fire started, Sanchez reported.

The cause of the fire remains under investigation.

(© Copyright 2018 CBS Broadcasting Inc. All Rights Reserved. The Associated Press contributed to this report.)