Abstract: EMPLOYEE #1 (A WELDER) AND EMPLOYEE #2 (HIS HELPER) WERE WELDING JOINTS OF PIPE IN A TRENCH, 25 FEET LONG, 10 FEET DEEP AND 6 FEET WIDE AT THE BOTTOM. NO SHORING OR OTHER SUPPORT HAD BEEN USED TO PREVENT CAVE-INS. A HEAVY CATTERPILLAR PIPE LAYER WAS PARKED 6 OR 7 FEET FROM THE TRENCH'S EDGE. A HEAVILY TRAVELLED STREET WAS NEARBY. A CAVE-IN OCCURRED IN THE AREA BETWEEN THE PIPE LAYING MACHINE AND THE TRENCH, PARTIALLY BURYING THE TWO EMPLOYEES. THEY WERE RESCUED BY THE FIRE DEPARTMENT. EMPLOYEE #1 SUFFERED A FRACTURE OF HIS 5TH VERTEBRA AND 4 BROKEN SPURS. EMPLOYEE #2 SUFFERED BROKEN RIBS, CHEST INJURIES AND LIVER FAILURE.