Abstract: SEVERAL EMPLOYEES WERE SETTING A PREFABRICATED, WOOD-FRAME WALL SECTION ALONG THE NORTH SIDE OF THE SECOND FLOOR EXTERIOR WALL. THERE WAS A STAIRWAY OPENING ALONG THE NORTH SIDE OF THE SECOND FLOOR WHICH WAS 10 FEET, 10 1/2 INCHES LONG AND 3 FEET, 1 INCH WIDE. AFTER THE WALL SECTION HAD BEEN SET INTO PLACE, EMPLOYEE #1 MOVED TO ANOTHER PART OF THE FLOOR TO PICK UP A LEVEL (TO PLUMB THE WALL). IT HAD STARTED TO RAIN, MAKING THE PLYWOOD DECK SLIPPERY. WHEN EMPLOYEE #1 RETURNED TO THE WALL, HE SLIPPED ON THE WET PLYWOOD AND FELL THROUGH THE FLOOR OPENING 17 FEET TO THE CONCRETE FLOOR AT THE FIRST LEVEL. HE RECEIVED ONLY MINOR BRUISES, AND WAS ABLE TO RETURN TO WORK THE NEXT WORK DAY.