An Auburn woman died in her bed Friday night after igniting her portable oxygen tank with a cigarette, the State Fire Marshal’s Office said.

Denise Fraser, 65, was found in her bedroom by her husband, Barry, when he returned from work that night, said Steve McCausland, spokesman for the fire marshal’s office. She had been on oxygen for the past year for health reasons.

Her remains have not been examined yet, but “typically what happens when smoking on oxygen (is that) you inhale a ball of fire,” McCausland said.

Fire damage was contained to her bed, he said.

McCausland said this was the second death from smoking on oxygen he knew of this year, and noted that oxygen installations carry warnings not to smoke while using them.