Abstract: On June 11, 2019, Employee #1, a truck driver employed by a construction company, had parked his 2008 Peterbilt semi-tractor and 2017 Kaufman detachable gooseneck lowboy trailer on a sloping access road at a construction site. He was using a Caterpillar skid steer secured on top of the trailer platform to raise the platform. As Employee #1 stood between the tractor and the trailer, the vehicle began to roll backward. The tractor's rear wheels ran over Employee #1, who was killed. The subsequent investigation determined that the truck's engine had been running; the parking brake had not been engaged; and the proper number and sized wheel chocks had not been used while the vehicle was parked on the incline.