One resident was trapped inside, while another was able to escape without any injuries by crawling out of the front door.
Neighbors who knew the victim didn't want to talk about the fire. But Lillington Police Chief Frank Powers said one of the firefighter's relatives lived across the street from the house and notified authorities about the blaze.
"It was a fully involved fire when I got here," Powers said. "The fire department was working hard."
Arson investigators were at the scene as a precaution, but authorities said they still don't know what started the fire.
They said the extensive damage in one part of the residence indicated the flames may have sparked there and then spread to the rest of the home.
"It probably took about four hours for them to extinguish it completely," Chief Powers said.
Crews were on the scene hours later watching for hotspots, while searching for clues that may have caused the fire.