Abstract: Employee #1 was run over by a tractor trailer he was operating. He had just backed his tractor and jeep trailer into a low-boy trailer loaded with an excavator. He was connecting the brake airlines to the low-boy, when the brakes of the trailer released. When the trailer brakes released, the entire rig began to roll downhill. Evidently Employee #1 did not set his tractor brake switches when he got out of the truck. Both switches were in the off position when observed later by the responding police officer and CSHO. Employee #1 had failed to set the parking brake and tractor protection valve. Employee #1 was run over and killed when the trailer began to roll because he was standing between the low-boy and jeep trailer to hook up the airlines. The wheels on the trailer were not chocked, but an expert approached in reference to this accident said chocks would probably not have stopped the combined weight of the truck, jeep trailer, low-boy, and excavator anyway.