— Investigators on Thursday were still looking into what set off an explosion at a Franklin County house that threw the homeowner from a chair and shook the homes of nearby neighbors.

The owner, Mike Oliver, was the only one home, at 599 Darius Pearce Road in Youngsville, around 6:15 p.m. Wednesday when the explosion propelled him into the air and set his house on fire.

He wasn't injured, and his wife and son were not home.

Although fire investigators haven't said what sparked the fire, Oliver and a Franklin County sheriff's deputy at the scene Wednesday night said it appears to have been caused by a propane tank explosion.

The explosion shook homes as far as a half-mile away, including Dave Clarke, who was watching TV with his son when he heard a loud boom.

He likened the explosion to an improvised explosive device.

"It just shook the whole house. All the windows rattled, motion lights came on, and my ears popped," Clarke said. "That's how bad it was. I thought something at my house blew up."

Oliver said a propane company was in the area earlier in the day but wasn’t sure why. His home has not run on gas since 2011, he said.