Abstract: Employee #1 and three other employees of an oil field maintenance firm were assembling 2 3/8 in. metal pipe, or flow line. The flow line was assembled using the rear drive wheel of a 1985 Ford F-350, 3/4 ton truck. The truck was jacked up with a coupling attached to the left rear hub to which 31 to 34 ft sections of pipe were joined. The drive wheel turned the flow line while additional sections of pipe were attached. A 36 in. pipe wrench was used on the last section of pipe to keep it from turning while being tightened to the previously completed sections. On the 11th joint, the rotating pipe bowed, causing the pipe wrench to flip under the flow line and strike Employee #1 in the right forehead, knocking him backward 6 to 10 ft. He died one week later from craniocerebral injuries. It was Employee #1's first day on the job. He was not wearing a hard hat nor was he trained to recognize the hazards associated with the job.