PORTLAND — Investigators say a woman who received life-threatening burns during a house fire Sunday was trying to put the fire out herself.

Julia Ball, 56, was taken by LifeFlight helicopter to a Boston hospital after receiving burns on 75 to 80 percent of her body, fire officials said. Her condition was not immediately available Monday evening, although such extensive injuries are often critical.

Sgt. Joel Davis, of the State Fire Marshal’s Office, said it appears the fire may be the result of smoking materials which ignited a living-room couch.

Ball, who owns the house at 250 Burnside Ave., may have fallen asleep while smoking or left the room after smoking materials fell down into the couch, he said. Investigators have not been able to interview her because of her condition, he said.

Ball apparently called her sister to say the house was on fire just before noon, he said. Her sister had someone else call the Portland Fire Department while she responded, and found Ball outside the apartment on fire, Davis said. The sister extinguished the fire on Ball.

The living room was extensively damaged but the Fire Department was able to save the house, Davis said.

Davis said the home did have working smoke detectors and Ball was apparently awake, but was burned trying to put out the fire. He said extinguishers at the house had not been discharged and investigators do not know how she was trying to put out the fire.