A Salt Lake man remained in stable condition Thursday morning at University Hospital after firefighters found him lying unconscious next to his burning mattress.
Medical crews believe the man, 41, suffered smoke inhalation and had a decreased level of oxygen entering his system when he lost consciousness Wednesday about 4:15 p.m., Salt Lake Fire spokesman Scott Freitag said.
Fire crews responded to the top floor of the man's apartment complex at 1277 E. 100 South. Damage to the building is estimated at $500, Freitag said.
Firefighters are still investigating what started the blaze and why the man didn't leave the building.
"The investigators ruled it as accidental," Freitag said. "Until they get a chance to talk to the guy and find out what happened it's really hard to tell."