A Dec. 30 house fire that killed 21-year-old Jason Gladd of Grove City was accidentally caused by his mother, according to Kirk Kurtyka, the state police fire marshal who led the investigation.

Gladd's mother, Theresa Donahey, 51, of 635 S. Center St., was lighting a cigarette when the tube to her oxygen machine caught fire, igniting a couch, said Kurtyka, who is stationed at the Beaver barracks.

She was able to get out of the two-apartment house in time, but wasn't able to warn her son, who was on the third floor in his bedroom at the time of the fire, he said.

She alerted neighbors, a woman and her 5-year-old daughter, who occupied the first-floor apartment and were able to escape unharmed. The burning residence took firefighters about three hours to bring under control. The fire broke out at about 2:30 a.m.

Police said Gladd died in the front upstairs apartment, adding it did not appear the apartments were equipped with smoke detectors.

Ms. Donahey was taken to United Community Hospital in Pine Township for treatment of smoke inhalation, then later transferred to Mercy Hospital in Pittsburgh, police said.

She was no longer in the hospital Thursday evening, according to a nursing supervisor, who did not know when she was released.