Abstract: At approximately 9:00 p.m. on June 17, 1997, Employee #1, a foreman with the Hayward Baker Company, and the swing shift crew, were changing out a damaged vibrator with a complete spare system. This included a dry bottom feed vibro-replacement stone column system that consisted of a lift arm, hopper, air pressure chamber, skip, follower tubes, stone feed pipe, and vibrator. There was one air pressure chamber with follower tubes and stone feed pipes lying adjacent to the system being changed, as well as a front end loader and a Manitowoc crane, neither of which were working at the time of the accident. Employee #1 was talking to two coworkers about the work plan. One coworker was supposed to provide light as it was dark in that area and another was to operate the front end loader and raise the cable in the vibro replacement system. Employee #1 was to use the crane to lower the boom for handling the system's generator cable. As the men dispersed to their assigned tasks, the operator of the front end loader started the engine and maneuvered the vehicle, using the headlight for visibility, when he saw Employee #1 near the ground, pinned between a lift arm and an air pressure chamber, and apparently gesturing for help. The loader operator advanced his vehicle and used the forks to lift the 50 ft combination gravel feed pipe/follow-on tube, which automatically lifted the air pressure chamber and freed Employee #1. He slumped to the ground, complained of severe abdominal pain, and then lost consciousness. Employee #1 was transported to St. Mary's Hospital, where most of his crushed intestines were removed. He also suffered kidney damage. The main causal factors for this accident were (1) failure to conduct a pre-construction survey to discern hazards such as the unstable support of the gravel feed pipe/follow-on pipe--one of the two welded lugs and supports was broken; and (2) failure to stack one lift arm/hopper assembly and another adjoining vibro-replacement stone column system to prevent them from falling or tipping over.