Abstract: ON SEPTEMBER 23, 1986, EMPLOYEE #1 WAS WORKING IN A TRENCH INSTALLING LATERAL SEWER LINE FROM A HOUSE, UNDER CONSTRUCTION, TO THE FREDERICK COUNTY MAIN SEWER LINE. THE TRENCH WAS 50 TO 54 FEET LONG, RUNNING EAST TO WEST, AND 7 FEET DEEP. THE NORTH SIDE OF THE TRENCH WALL WALL WAS VERTICAL, WHILE THE SOUTH WALL WAS SLOPED BACK FROM 4 TO 6 FEET. THE SLOPE BEGAN 16 INCHES ABOVE THE BASE OF THE TRENCH. THE TRENCH WAS 24 INCHES WIDE BEFORE THE BEGINNING OF THE SLOPE. THE SOIL WAS DRY, WITH A HIGH CONTENT OF SLATE ROCK. EMPLOYEE #1 WAS ENGAGED IN INSTALLING THE SEWER LINE, AND WAS MOVING AROUND THE TRENCH WHEN A ROCK, ABOUT 6 FEET LONG, 3 FEET WIDE AND 4 INCHES THICK, SLID DOWN INTO THE TRENCH WHERE HE WAS LOCATED. THE EMPLOYEE'S FEET WERE ON THE SOUTH SIDE OF THE SEWER LINE. THE SLIDING ROCK AND SOIL TRAPPED THE EMPLOYEE'S FEET BETWEEN THE PIPE AND THE SOUTH SIDE OF THE TRENCH. THE EMPLOYEE WAS BURIED UP TO HIS WAIST. HE WAS REMOVED BY RESCUE PERSONNEL AND TAKEN TO THE HOSPITAL, WHERE HE WAS CHECKED OVER AND X-RAYED FOR BROKEN BONES. HE WAS FOUND TO HAVE SUFFERED ONLY BRUISES. NO OTHER PORTION OF THE TRENCH GAVE WAY OR CAVED-IN. HOWEVER, THE TRENCH SIDES WERE NOT BRACED, SLOPED (EXCEPT FOR THE SOUTH SIDE) OR OTHERWISE SESCURED TO PREVENT A CAVE IN. EMPLOYEE #1 WAS NOT WEARING ANY HEAD PROTECTION WHILE WORKING IN THE TRENCH. THE EMPLOYEE HAD NOT RECEIVED ANY TRAINING FROM HIS EMPLOYER ON THE HAZARDS ASSOCIATED WITH WORKING IN TRENCHES.