Abstract: Employee #1 was sitting in the bottom of a 32 in. wide trench that was being dug for the installation of a 6 in. PVC sewer line/pipe. The trench was being dug east to west near the center of an asphalt-surfaced street. A backhoe was positioned to excavate the material, which was mostly gravel, sand, and rock. (The area had previously been a river bed.) Employee #1 was pushing on the end of the pipe with his leg when the trench caved in and he was struck by the falling material. He was hospitalized with a broken back. According to a coworker, there was little or no wall. It had fallen away, leaving an overhang of asphalt and exposing 12 to 18 in. of PVC pipe.