A deadly fire tore through an Upper East Side apartment early yesterday morning, killing an 89-year-old woman and her son, law enforcement authorities said.

The blaze, which the fire department said it responded to just after midnight, killed a wheelchair-bound woman, Anna Roberts, and her 65-year-old son, William Roberts, in their third-floor apartment at 327 E. 93rd St., officials and neighbors said.

“My entire apartment was full of smoke,” a fifth-floor resident of the building, Dan Guertin, said. He said he woke up when he heard the fire trucks outside and then fled to the roof. “I couldn’t see my hand in front of my face.”

Most of the other residents were out of town for the weekend, he said.

Twelve fire trucks and about 60 fire and EMS personnel responded to the incident, fire officials said. Two firefighters sustained minor injuries, officials said.

“The fire was so intense and spread so fast,” Mr. Guertin, 35, a commodities researcher at Lehman Brothers, said. “I don’t think there was much they could have done.”

Roberts spent much of his time sitting on his stoop, making small talk with passers-by, and taking care of his elderly mother, neighbors said.

“It’s very upsetting; everybody liked him,” a neighbor who lives down the street, Josephine Moffi, said. She called Mr. Roberts “a very good son.”

“I always said, ‘God is going to bless you. Your bed is made in heaven,'” she said.

The Robertses had lived in the building for decades, Mr. Guertin said. Anna Roberts rarely left the apartment, he added.

The apartment was bolted shut yesterday afternoon, the third-floor hallway walls were charred black, and the stench of fire permeated the building. A blackened ironing board leaned against the hallway wall.

The co-op board had finished renovating the building Friday, Mr. Guertin said. Just days before the fire burned the walls, the building had received a paint job, new tile floors, and new marble stairs, he said. On the third floor, the ceiling and top of the walls were burned black, while blue tape used to paint still lined the floor moldings.

The fire department said it is investigating the cause of the fire, and police said they do not suspect criminality.