Abstract: Employee #1, a welder, was working on a 40 ft long conveyor belt structure. It had been lifted in place by a front end loader, and the legs that supported the raised end of the structure were positioned beneath it. The loader was then disengaged from the conveyor's upper end and removed from a support position. The welding trailer had been backed under the conveyor, and Employee #1 climbed onto the trailer to weld the leg support to the frame of the conveyor structure. The legs and the structure had not been secured together in any fashion, and the structure rested on the cross-members of the legs. Employee #1 had his hood on and was getting ready to strike an arc when the weight of the structure caused the legs to rotate. The structure fell, pinning Employee #1. He sustained a dislocated foot and severe contusions to the thigh and neck.