Abstract: On October 1, 2011, Employee #1, who had been employed by a service station for two months as a cashier and a propane tank filling attendant, was filling a small, 5-gallon propane tank. The large 450-gallon propane tank was owned by Suburban Propane and leased to the employer, Field Energy Corporation. The LPG (liquid petroleum gas) tank was apparently manufactured by Buehler in 1969 and had a Serial Number of B-47487. The Pressure Vessel Permit State Number was L006328. As seen on the surveillance video, Employee #1 filled the 5-gallon tank and vapors were seen released from the pressure relief valve. Immediately afterward, a fireball explosion of propane vapor occurred in front of the propane filling operation. Employee #1 sustained first and second degree facial burns and was hospitalized for 10 days after surgery. The serious injury was reported to the Division on November 3, 2011. The Pressure Vessel Unit (PVU) compliance officer, who issued the permit in 2009, rechecked the propane tank for safety and regulatory compliance and assisted with the District Office/PVU joint accident inspection. The source of the spark that initiated the propane fireball could not be determined.