Abstract: Employee #1 was changing a tire on the rear right side of a truck weighing 30,000 lb. There was a 42 ft trailer connected to the truck with a load of steel weighing 35,000 lb. The bay area was level where the truck was parked, but there was a 6 in. drop in elevation outside the bay door for at least 30 ft. Employee #1 had finished his work and was putting his tools away when the truck started to roll backward over his left leg and pelvic area. Employee #1 died while at the hospital. The truck and trailer, moving at 5 mph, rolled approximately 70 ft before a coworker could stop it. Employee #1 had released the brakes on the truck prior to finishing his work so he could spin the wheel to match up the valve so that the wheel would not wobble when the truck was driven.