Abstract: On May 2, 1997, Employee #1 and six coworkers were part of an excavation crew that was installing a 12 in. sewer line in West Haven, CT. At the close of work on Friday, the crew laid the last pipe approximately 10 ft south of the existing gas main and they placed a stake at the opening of the pipe so they could find it when work resumed on Monday. They left the 6 in. gas main and the 12 in. water main exposed. Steel plates were then placed over the trench so the road could be reopened to local traffic for the weekend. Work operations continued on May 5. The goal was to continue installing the 12 in. sewer line in a northerly direction, to remove the old manhole and replace it with a new one, and to install approximately 100 ft of new sewer pipe in an easterly direction. The third excavation, where the new pipe was laid on Friday but left uncovered, was 12 ft wide by 10 ft 6 in. long by 8 ft deep. Employee # 1 and a coworker entered this sloped excavation and went underneath the utilities so the crew could get the proper grade and clean around the opening of the newest pipe. The coworker was shoveling soil while standing between the water and gas mains. Employee #1 was on the surface, shoveling soil from near where the storm drain had been removed when the trench partially collapsed and Employee #1 fell in. He suffered a fractured back, for which he was hospitalized. When CSHO investigated, they observed an open excavation and trench without any shoring or sheeting.