A Chattanooga woman received serious burns late Monday afternoon when fire broke out in her bedroom.

Chattanooga firefighters responded to the emergency at 3610 4th Ave. shortly after 5 p.m, according to Bruce Garner, public information director for the Chattanooga Fire Department. He said when firefighters arrived on the scene, they observed an oxygen machine was on fire in the front yard.

Capt. David Barie with Engine 9 said a smoldering set of box springs and mattress were also in the front yard. All of the burning materials had been carried out by people who were in the house at the time, Mr. Garner said.

When the firefighters went inside the house, they discovered a woman who had been seriously burned. Lt. Anthony Moore with the Fire Investigation Division said the 52-year-old woman was on an oxygen machine, but was also smoking cigarettes.

Lt. Moore believes the oxygen tubing caught on fire first and then quickly spread to the woman’s clothes and bed linens. The woman’s husband and daughter put the fire out, but the burns were severe.

The woman was transported to Erlanger Medical Center by Hamilton County EMS with second and third degree burns to her upper torso.

Hours later, she was transported to a burn unit at Vanderbilt University Medical Center, where this morning she was listed in critical but stable condition. The cause of the fire will be listed as accidental Mr. Garner said.