Abstract: On December 15, 1998, Employee #1, a truck driver, was in the process of pressurizing the repaired trailer in order to test for leaks. The driver climbed on top of the trailer apparently trying to secure the number 3 dome lid cover so that a proper seal could be obtained. Another employee, the mechanic, and Employee #1 descended the trailer and both decided to pressure test the trailer for leaks. Employee #1 started his truck motor and engaged the PTO, which runs the blower unit of the truck. The mechanic then proceeded to the front trailer to check another possible leak reported by the driver. The mechanic observed Employee #1 climb up on the draw bar of the second trailer, climb up the trailer ladder, and heard the driver make an exclamation. The mechanic then observed the driver get on top of the trailer while the blower was still activated, walk across the top of the trailer, and kneel down over the number 3 dome lid. Approximately two minutes later the mechanic heard an explosion and observed Employee #1 hit the ground. The employee died as a result of his injuries.