Abstract: On January 12, 2009, Employee #1, #2, #3, and #4, two refinery operators and two contractors, were standing in a shed, located approximately 230 ft away from a petroleum storage tank, known as Tank 105. A large vapor cloud was released from the tank, which was ignited by an undetermined ignition source, causing a massive flash fire. Employee #1, #2, #3, and #4, sustained serious burns after they were engulfed by the flame front. All four were hospitalized. The storage tank burned until the flames were extinguished by the South Davis Metro Fire Agency and local refinery fire brigades, early the following morning.