Abstract: ON DECEMBER 8, 1987, FOUR EMPLOYEES WERE PLACING 15 INCH DIAMETER AND 13 FEET, 11 INCH LONG PVC SEWER PIPE IN A TRENCH. THE TRENCH WAS 12 FEET, 8 INCHES DEEP, 46 FEET LONG, 42 INCHES WIDE AT THE BOTTOM AND 13 FEET, 8 INCHES WIDE AT THE TOP. A 14 FOOT LONG, 6 FEET HIGH AND 42 INCH WIDE TRENCH BOX WAS BEING USED IN THE TRENCH TO PROVIDE PROTECTION FROM A CAVE-IN. BECAUSE FLOODING HAD DISPLACED SOME BACK FILL MATERIAL IN THE TRENCH, IT WAS BEING REMOVED FROM ATOP THE PIPE. TO FACILITATE THE WORK THE TRENCH BOX HAD BEEN MOVED DOWN THE TRENCH A LITTLE. THREE EMPLOYEES WERE WORKING IN THE TRENCH; TWO INSIDE THE TRENCH BOX AND ONE (EMPLOYEE #1) 4 TO 5 FEET OUTSIDE THE TRENCH BOX. A LARGE (1 BY 3 BY 5 FEET) CHUNK OF THE TRENCH SIDE CAVED IN AND STRUCK EMPLOYEE #1 IN THE CHEST. THE EMPLOYEE DIED OF MULTIPLE FRACTURES, A CRUSHED CHEST AND A PUNCTURED AND LACERATED LUNG. THE ACCIDENT WAS CAUSED BY THE FAILURE TO RECOGNIZE THE HAZARD OF A POSSIBLE CAVE-IN, NOT TAKING ADDITIONAL PRECAUTIONS WHERE FLOODING, VIBRATIONS, AND ADJACENT BACK FILLED CONDITIONS EXIST, AND NOT PROVIDING AND REQUIRING USE OF THE PROTECTION OF PROPER SHORING OR SLOPING OF THE TRENCH.