Abstract: At approximately 1:50 p.m. on September 23, 1988, Employee #1 and a coworker, driving separate tractor trailers, arrived at the loading dock of Weirton Ice and Coal, Weirton, WV, to unload coke pieces onto a barge. While they were waiting in the truck staging area for an empty barge, the coworker moved closer to the dock so Employee #1 could park his vehicle nearer to a truck washing station. The coworker then went to get a drink of water. He left his vehicle parked with the engine running, engaging the glad hand glide valve and the emergency air brake system from the normal mode. Employee #1 began to hose off his vehicle and was on the passenger's side when the coworker's truck moved backward and crushed him between the two tractor trailers. The moving vehicle then glanced away, allowing Employee #1 to escape from between the trucks and crawl away. However, he died from his injuries. A 1.5-in. O-ring (valve type RE-6) on the interior of the trailer that controls the pressure on the air brake system had malfunctioned, allowing the air pressure to slowly drain from the trailer's air tank.