Abstract: At approximately 11:00 a.m. on April 19, 1993, Employees #1 and #2 were working in a trench. They were operating a pneumatic winch machine that was pulling a 20 ft long 12 in. diameter plastic pipe with a wire rope cable through a 16 in. cast iron main gas line pipe. The plastic pipe became stuck in the cast steel dresser coupling, causing the cable to become taut. The winch attempted to continue wrapping the cable and then broke free from its anchorage at the concrete base and pinned Employees #1 and #2 against the shoring. Employee #1 suffered severe bruises to his left leg and was hospitalized. Employee #2 suffered bruises to both legs.