Abstract: On September 6, 1984, Employees #1 and #2 were laying pipe in an 8 to 9 ft deep trench adjacent to Highway 20, south of Thermopolis, WY. A backhoe operator had dumped a load of soil over the PVC sewer pipe. Employees #1 and #2 compacted the soil around the pipe and walked out of the trench. Employee #2 then realized that the bell housing of the newly laid section of pipe had not been greased (which is the last step after pipe is laid), and returned to the trench to do so. Employee #1 followed him and was approximately halfway down the trench when the west wall, which was adjacent to a previously excavated utility trench, sloughed off. Both workers were buried. Employee #1 was enveloped by a small pocket of air and stayed conscious. He yelled, and was immediately located and pulled to safety. Rescuers had to search for Employee #2, who died of suffocation.