For the second time in a year, a fire apparently caused by her own careless smoking trapped a District woman in her bedroom early yesterday morning, this time with deadly results, neighbors and fire officials said.

The blaze was extinguished just 11 minutes after it was reported at 1:48 a.m., but it was too late for the woman, who was found sitting crosswise on her charred bed, a wheelchair nearby, officials said.

The name of the victim, who was 70 years old, was not released because relatives have not been notified. But neighbors described her as a private woman who spent at least the last 20 years living on the 1200 block of Fern Street NW.

A neighbor, who declined to give her name, said the woman was known as Miss Sally. Although she guarded her privacy, the woman took the neighbor and her husband into her confidence. "Basically, she was a very lonely person," the neighbor said. "She has family, in the West Coast, but she didn't keep in touch. Once, when she was sick, we called but nobody came."

She was a career military person and worked at Walter Reed Army Medical Center, which is across the street from her house. An accomplished amateur photographer and beautiful woman when young -- she would show pictures of herself, and said Hollywood once was interested -- she spent most of her life alone.

"When her husband got killed in the war, she said she would never get married because she was so much in love. And she never did," the neighbor said. "She was so lonely, she would cry. Sometimes, I would go over and she would say, 'Sit down. Don't go.' "

About a year ago, the woman accidentally cast a cigarette into a shopping bag, but the fire was extinguished by firefighters without causing much damage, the neighbor said. Yesterday's blaze apparently started the same way, fire officials said, although the fire is still under investigation.

Next-door neighbor Louis Scherr said he heard a noise and looked out his window, across the alley from the woman's house. He said he tried to enter the house, but smoke on the first floor drove him out.

The house has two apartments, one in the basement and the other on the second floor. Scherr knocked on the basement window and awoke the resident, who then climbed to the second floor using his construction ladder. The three other people in the building escaped uninjured.

The woman's belongings -- including a large metal file cabinet and personal papers -- were out in the back yard yesterday.

"Her whole business is laying out there in the back yard," said the downstairs tenant, a construction worker from Indiana who did not want to give his name.