Abstract: On September 27, 2007, Employee #1 was called out to a site to troubleshoot excessive smoking and unusual vibrations coming from an engine. The mechanic had instructed the facilities manager of the hospital to run the engine at 900 RPM, normal operating speed. At one point, the engine was shut down, and when the motor reached about 200 RPM during the deceleration process, an explosion came from the crankcase, igniting oil vapors and blowing out several crankcase inspection covers. Employee #1 did not lose consciousness from the explosion and was taken to the emergency room at Los Angeles, County USC Medical Center.