A 66-year-old woman has died days after reportedly lit a lighter while she was on oxygen in a Pennsylvania hospital, sparking a fire.

Val. E. Cooper, of Williamsport, was burned when her hospital gown caught fire in her sixth-floor room at the UPMC Susquehanna Williamsport Regional Medical Center about 3:40 p.m. Tuesday, the Williamsport Sun-Gazette reported.

Cooper was being treated for medical and mental health issues, and staff were unaware she had a lighter, according to the report. The Associated Press, citing fire officials, said Cooper smoked, but that's prohibited in the hospital -- her cigarettes and another lighter were stored in a lockbox.

Two nurses tried to douse the flames with a sheet, and a third put it out with an extinguisher, the Sun-Gazette said.

Cooper was eventually flown to a burn center in the Lehigh Valley, where she died Thursday afternoon, the Lehigh County Coroner's Office said in a news release Friday. Her death was due to complications from her injuries and ruled an accident.

Two of the nurses in Williamsport were treated for burns to their hands and discharged, the Sun-Gazette reported.

Steve Novak may be reached at snovak@lehighvalleylive.com. Follow him on Twitter @type2supernovak and Facebook. Find lehighvalleylive.com on Facebook.