BELLEVIEW, Fla. -- A Marion County man who needed an oxygen tank to help him breathe died Thursday morning when his house caught on fire. Investigators said the victim was found on the porch of his home on Robinson Road overnight.

Eyewitnesses say they heard explosions at the home. Fire investigators said the explosion came from an oxygen tank inside the house that blew up after firefighters arrived.

The wood-framed home on Southeast Robinson Road (see map) didn't stand a chance against a fierce wall of flames that consumed it in the middle of the night. Amongst the rubble, firefighters found the body of an elderly man lying on the front porch.

"I went to the bedroom and he wasn't there, so I thought maybe he had seen the fire and ran out the front door. His bedroom is right next to the front door," said one of the man's roommates.

According to two women who live there, the victim is 64-year-old Jerry Hale. He was a family friend who lived in the house for six years. They said he often got up in the early morning hours to smoke.

When they went to his room to warn him about the fire, he wasn't there. By that time, the front of the home was engulfed in flames and the two women escaped through a back door.

According to investigators, the fire started in the porch. They said they can't rule out careless smoking as a possible cause. For one, the porch had no electricity. Also, a police dog didn't track any accelerants.

Investigators removed a few samples from the porch. They'll send them to the crime lab, but as is often the case it could take several weeks before they know for sure what happened.