Angel Alcazar -- the owner of six cats -- was cooking pork chops inside his apartment on Gouverneur Ave. in Riverdale at about 5 p.m. when a grease fire broke out, neighbors said.
As Alcazar tried to put out the blaze, at least one of his felines got too close and caught fire, they said. The torched tabby then ran around the home, setting everything it touched on fire.
"I looked outside my window ... I saw nothing but flames," said resident Theodore Oakes.
The fire quickly began consuming both the third and fourth floors of the building, which has 67 apartments, officials said.
Disabled tenant Suzanne Guthridge, 52, was sitting in her home down the hall when she smelled the smoke -- and the cry of a kitty.
"I opened the door for the cat," Guthridge said. "He came through and I shut it because the smoke was overwhelming. It was really scary.
"That whole area was full of smoke," she said. "It was unbelievable. You could feel the heat."
Five of the cats, including the one that was burned, are believed to have died.
Two victims were in critical condition at Jacobi Hospital, authorities said.
One woman -- who tenants said has an autistic child -- was unconscious and had extensive burns as she was pulled out of the building near Sedgwick Ave.
"She looked like she was burnt from her breasts down to her groin," said tenant Whitney Martin, 54. "EMTs had her stretched out. She was nonresponsive."
A mewling black cat -- the one Guthridge saved -- is believed to be the only one of Alcazar's cats that survived. It was found crouched in the corner of the third-floor hallway hours after the fire was put out, witnesses said.
"(Alcazar) didn't treat his animals very well," Guthridge said. "The house always smelled like cat urine and cat poop. I did call PETA (on him). They said they were gonna send somebody out, but nothing was ever done."
Alcazar, who may have been injured in the blaze, was taken away for questioning as FDNY marshals investigated the cause of the blaze, witnesses and a department spokesman said.
His neighbors' homes were damaged beyond repair, tenants said.
"I have no idea (where I'm going to go)," she said. "I have a son who lives in the city and my grandson who lives with me. Right now, we don't know."
"(Water) flooded everywhere, my living room, my bedroom, my bathroom," added Oakes. "It was coming down my wall like a fire hydrant."
Oakes' wife, Shirley, said she tried to salvage some of her valuables.
"We grabbed what we could and ran out the house," she said. "I didn't want the ceiling to come down on me."
More than 100 firefighters spent an hour and a half putting the fire out.
The Red Cross was helping to relocate displaced residents Friday night.