NEW YORK (CBSNewYork) — One person was killed and another is fighting for their life after a fire early Wednesday morning on the Upper East Side.

Witness video shows flames shooting out of the windows of an apartment building at the corner of 82nd Street and Second Avenue at around 8:30 a.m.

READ MORE: Woman Wanted For Allegedly Punching MTA Employee In The Face At Times Square Subway Station

Saad Khallaayoun lives next door and woke up to an overpowering smell of smoke.

“I saw smoke in the roof. By the time I’m coming down the super came and said, ‘You have to get out of the house.’ So we grabbed the passports, my kid, and our dog and we left,” Khallaayoun told CBS2’s Jessica Moore.

The building has a total of six apartments, three of which were extensively damaged, fire officials said. Two residents, 81 and 83, were rushed to Lenox Hill Hospital, where the 83-year-old died.

“One of our impediments was the fact there was a large amount of contents in the apartments, which hinders our fire advance and our searches,” FDNY Deputy Assistant Chief Michael Ajello said.

Piles of belongings taken from the second-floor apartment where the fire started later littered the sidewalk. Neighbors said the man who lives there was a self-professed “collector.”

READ MORE: Metro-North Penn Station Access Project Allowed To Resume, 4 New Stations To Be Added In The Bronx

“I think it was a fire danger because clothing … was piled to the ceiling. You couldn’t walk in normally. He never used his kitchen. He had a very unlivable condition,” neighbor Robert Tibor said.

The Department of Buildings told CBS2 it had not received any complaints about the building in more than 10 years and has no record of a hoarding situation there.

Neighbors remembered the victim and said they’re thankful to be alive.

“I feel sorry for him and his family. We’re very lucky,” Khallaayoun said.

One firefighter suffered minor injuries. He was treated at Weill Cornell and released. At last check, the other resident was still in critical condition.

The Red Cross is helping the residents who are now displaced as the fire investigation continues.

MORE NEWS: Police Trying To Identify Man Wanted After Woman Stabbed On Brooklyn Subway Platform

CBS2’s Jenna DeAngelis contributed to this report

Jessica Moore