Molly Harris, 63, of the 1500-block of North Hoyne Avenue, was pronounced dead at John H. Stroger Hospital of Cook County at 3:15 p.m., according to the Cook County Medical Examiner's office.
The fire in the 1500-block of North Hoyne Avenue was already out when firefighters arrived after receiving a report of smoke in the building at 5:11 a.m., according to Fire Media Affairs. The fire was put out by a sprinkler, but not before the woman's bedding caught fire.
Fire officials said the fire was caused by smoking while using oxygen.
In the second floor apartment firefighters found the Harris with extensive burns covering 90 percent of her body. She was taken by ambulance to Stroger Hospital where she later died.