Abstract: At approximately 2:00 p.m. on February 7, 2008, Employee #1 and a coworker were working as welders. They were employed by Irwin Industries Incorporated. They were welding at the Exxon Mobil Hill Lease in McKittrick, CA. They were tack welding a 356-millimeter (14-inch) slip-on flange onto a diatomite york scrubber inlet pipe. Serial number 2388g had been installed approximately 457 millimeters (18 inches) inside the pipe from the end where the welding operation was to be conducted. The purpose of installing the inflatable plug was to isolate any residual flammable gas in the pipeline from the welding process. Employee #1 had just completed tack welding the bottom of the flange to the end of the pipe and was tack welding the top of the flange, when the inflatable plug blew out of the pipe, striking Employee #1 in the head. Employee #1 was airlifted to the Kern Medical Center in Bakersfield, CA, for treatment. Employee #1 was admitted to the hospital intensive care unit due to complications after suffering numerous broken teeth, extensive lacerations to his head, mouth and throat area. Irwin ndustries Inc. reported this accident to the Cal OSHA Van Nuys District office the same day at 5:30 p.m. The Van Nuys District Office transferred the employer's report to the Cal OSHA So. Cal PSM District Office on February 8, 2007.