Abstract: At approximately 2:00 a.m. on May 4, 1991, Employee #1, a marshaler on the ramp at Ontario International Airport and her crew were using tugs with dollies and a K-loader to put containers onto a DC-8 aircraft The K-loader is a lifting device as well as a conveyor; the operator's platform is elevated to the height of the aircraft entrance and the bridge portion of the K-loader moves vertically. Employee #1 had been marshaling in tugs, dropping the locks on the dollies, and moving the containers onto the K-loader bridge. During one procedure, she approached the dolly before the K-loader bridge had descended to its lowest point. The bridge struck her buttocks, crushing her between its moving and stationary parts. She sustained serious injuries, for which she was hospitalized. There had been disagreement between Employee #1 and coworkers concerning the practice of lowering the locks before the K-loader bridge was completely lowered.