Abstract: AT APPROXIMATELY 1430 HOURS ON JUNE 15, 1987, EMPLOYEE #1 WAS INSTALLING SHORING IN A TRENCH THAT WAS 30 FEET LONG, 2 1/2 FEET WIDE AND 6 1/2 FEET DEEP. THE SHORING CONSISTED OF 4 FEET BY 8 FEET SHEETS 3/4 INCH PLYWOOD. THE PLYWOOD SHEETS WERE BRACED AT THE BOTTOM BY PIECES OF 4 BY 4, AND AT THE CENTER BY HYDRAULIC JACKS. THE PLYWOOD SHEETS HAD BEEN EMPLACED AND WERE AWAITING THE SETTING OF THE HYDRAULIC JACK. EMPLOYEE #1 WAS STANDING IN THE PROTECTED AREA OF THE TRENCH (WHERE SHORING WAS ALREADY SECURED) REACHING THROUGH TO SET THE HYDRAULIC JACK IN PLACE FOR THE NEXT SECTION. HE SUDDENLY LOST CONTROL OF THE JACK AND, INSTEAD OF DROPPING IT, STEPPED FORWARD INTO THE UNPROTECTED PORTION OF THE TRENCH. THAT'S WHEN THE TRENCH CAVED IN, PINNING HIM BETWEEN THE SHEETS OF PLYWOOD. HE WAS PINNED FOR APPROXIMATELY TEN MINUTES BEFORE HE COULD BE RESCUED. HE REMAINED CONSCIOUS FOR ABOUT THREE MINUTES, TALKING TO THE OTHER EMPLOYEES. HE WAS TRANSPORTED, STILL UNCONSCIOUS, TO THE ST. CLOUD HOSPITAL.