OKLAHOMA CITY - Just before 7:30 a.m., a fire broke out at a home at 3212 South Lee Avenue.
Fire crews were able to knock it down quickly but then discovered there was one adult male in the home they thought was vacant.
According to the Oklahoma City Fire Department, the man was just inside the door right by the couch.
He was the only person in the house.
Fire crews and EMSA worked on the victim at the scene, but he was transported to Integris Southwest Medical Center and later pronounced dead sometime around 9:50 this morning.
The man's identity has not yet been released, but neighbors tell NewsChannel 4 he was an elderly man who kept mostly to himself.
The Oklahoma City Fire Department still hasn't determined the cause of the fire, but there is no indication of foul play at this time.
Investigators say the home did not have electricity and didn't have gas hooked up.
But they say it appeared the man was using an inner tube to illegally pipe gas into the home.
No one else was injured.
This is still a developing story. Check back for updates.