Family members have identified the man as Charles Boussad who lived in the trailer.
Fire fighters were called out to Central Valley RV Repair on the 5300 block of E Home Ave. Central Valley RV repair is a family business and Boussad was a family member.
Boussad's cousin, Mark Eggert, says Boussad had lived in his trailer on the property for about 15 years. Boussad is also cousins to the business owner, who is Eggert's brother.
"He just lives here, he just helps out and stuff and watches the place," Eggert said.
Eggert says Boussad was in his 60s. He worked in the offices of courtesy moving in Fresno, and volunteers for the Fresno fire department. He was reportedly inside the trailer when it burst into flames, but he's not sure how he got out.
"Burns on his hands and side of head," Eggert said, "they're mainly concerned about the flash to his face. (They're) concerned about his breathing."
Fresno Fire fighters say he had second degree burns and though they're painful, he is expected to survive. Battalion Chief Thomas Cope says Boussad was out of the trailer by the time they arrived, he offered keys to the building nearby which had sustained fire damage.
"He came out of the darkness about 10 minutes after our arrival," he said, "and we saw that he was pretty badly burned."
Fire fighters suspect a propane leak maybe the cause of the explosion.
"He went inside and checked the stove, turned the stove off, he was checking the pilot lights and then presumably an appliance or some other item inside the trailer ignited the leaking propane," he said.
Fire fighters aren't sure what caused the original spark but described something like a fireball happening inside the trailer.
"The propane tanks did not explode," Cope said. "The propane had leaked into the trailer so the propane and air mixture inside the living space caught fire and exploded."
The fire also damaged Central Valley RV Repair's paint shop, including an RV that was inside the building.
Fire fighters are still investigating the fire. They estimate the damage at around $25,000.