Abstract: At 2:00 p.m. on May 19, 2005, Employees #1, #2, and #3 were, with two coworkers, working for Pool Well Services Company at a Matrix Oil Corporation well in Whittier, CA. Pool Well Services had been contracted by Briones Oilfield Services, the operator of the Matrix lease, to desand the well. The day before, the workers had set up a portable workover rig and a blowout preventer (BOP) on the well for the desanding. The incident site consists of seventeen oil wells originally drilled in the 1970s and located 10 feet below grade in a 75-ft by10-ft cellar. On the day of the accident, workers were pulling tubing from the well, when the tubing became stuck at a depth of 300 to 500 feet in the 8000-foot deep well. While holding the tubing flange 10 feet above the BOP with the workover rig, Employee # 3 instructed the crew to backflush the tubing. A mud pump was set up to inject water into the tubing. As this was going on, the diesel engine on the workover rig began to overrun uncontrollably; flammable vapors from the well were entering the engine's intake manifold. To reduce or stop the gaseous release from the well, Employee # 3 directed Employee # 1 to release the tubing flange and drop it back onto the BOP. Employee # 1 released the tubing and ran to the control panel at the center of the workover rig to engage the emergency stop device and shut down the diesel engine. Suddenly, a flash fire occurred at the engine; it traveled back toward the source of the release at the wellhead. Fire engulfed the area where Employee # 1 was standing. Employee # 3 ran from the derrick end of the workover rig toward Employee # 1 to extinguish the fire on Employee # 1's clothing. Employee # 2 jumped from the top of the mud pump control platform and ran toward the entrance gate. One coworker, 75 feet from the well when the fire broke out, ran toward the gate and was unharmed. A second coworker, 40 feet from the well, also escaped toward the gate unharmed. Employees #1, #2, and #3 all received burns. Employee #1 died from his injuries. Employees #2 and #3 were not hospitalized.