Abstract: At approximately 12:45 p.m. on August 1, 1984, Employees #1 and #2 were laying a length of 10 inch sewer pipe in a 30 in. wide by 52 ft long 13 ft deep trench. The walls were vertical, unshored, and unbraced, and no trench box was in use. The east wall collapsed, burying Employee #1 to his chest and Employee #2 to his waist. During rescue operations, the wall collapsed again, burying Employee #3 to his chest and completely covering Employees #1 and #2. Employee #1 suffered numerous bruises and swelling of the lower legs and feet and Employee #2 sustained injuries to his knees and upper legs; both were hospitalized. Employee #3 suffered a shoulder injury and a broken collarbone.