Witnesses described intense flames shooting from the structure on Nostrand Avenue near Beverly Road.
"The flames were shooting out, literally," said neighbor Rich Savaille. "It's like you could feel the heat from where I'm standing."
The fire quickly spread through a vacant storefront and into two upstairs apartments.
Savaille said he woke suddenly as chaos unfolded next door.
"I woke up this morning to my brother saying, 'Fire, fire - everybody get out.'"
His brother, Edwin Savaille, recalled hearing a disturbance shortly before the flames erupted.
"I heard an argument this morning through the walls, and then, like, ten minutes later, that's when I heard someone yell 'fire.'"
Authorities say the fire broke out just before 7 a.m. A 65-year-old man and an 86-year-old woman were killed. Neighbors say the victims - believed to be mother and son - had lived on the block for decades.
The man was well known in the community for his passion for baseball.
"He was a baseball coach. As a sports fan, we'd always talk about the game," one neighbor said.
Neighbor Evan Clark said he had just seen him days earlier and was expecting him at a community celebration.
"I think they won some type of championship yesterday, and he was supposed to have a ceremony today," Clark said. "Everybody knew him. He was pretty famous around here."
Two women who lived in a third-floor apartment were rescued and taken to the hospital in stable condition. One neighbor said the rescue effort required quick, creative action.
"They actually had to take them out through my bedroom window," the neighbor explained. "The windows connect to a fire escape, so they brought them down that way."
The building's landlord, who also owns the vacant storefront, says he is now working to determine next steps as residents assess the damage.
"A little water damage, but nothing crazy," he said.
As investigators work to determine the cause of the fire, the community is left grappling with loss.
"We're just trying to absorb the shock right now," a neighbor said.
Officials have not yet said how many people have been displaced. The cause of the fire remains under investigation.
----------
* Get Eyewitness News Delivered
* More Manhattan news
* Send us a news tip
* Download the abc7NY app for breaking news alerts
* Follow us on YouTube