Abstract: At approximately 5:55 p.m. on July 25, 1996, Employee #1 was attempting to drive a track-type bulldozer onto the bed of a tractor trailer. A coworker was giving directions and watched as Employee #1 began to back the vehicle. The tractor trailer was apparently parked on the north shoulder ditch line, and was at a slight angle toward the shoulder of the road. The coworker verbally warned Employee #1 two or three times that the bulldozer was beginning to slip off the trailer toward the shoulder, but he continued backing. The bulldozer slid off the trailer and tipped over, pinning Employee #1's chest under the vehicle's rollover protection structure (ROPS). Employee #1 was transported to the hospital, where he later died. The accident was caused by the trailer bed not being on a level surface, and by Employee #1 not wearing his seat belt.