Abstract: AN EMPLOYEE FELL 21'10" WHILE INSTALLING CORRUGATED SHEET METAL DECKING ON A SINGLE STORY STRUCTURAL STEEL BUILDING. DECKING HAD BEEN SET ON TOP OF BAR JOISTS THE PREVIOUS DAY. EE'S #1 AND #2 STARTED LAYING DECKING AWAY FROM THE BUNDLE TOWARD THE WEST END OF THE BLDG. WITH ONE ON EACH END OF THE 18'X 3' LONG SHEET THEY ALIGN THE SHEETS TOWARD THE BUNDLE. THIS PROCESS CONTINUED UNTIL THERE WERE APPROX100-110 UNSECURED CORRUGATED SHEET METAL POSITION ACROSS THE BAR JOISTS, TOP OF BAR JOISTS 4" WIDE. EMPLOYEE #1 LAYED WASHERS IN THE LOWER GROOVE OF THE SHEET METAL, AND EMPLOYEE #2, FOREMAN CAME BEHIND HIM WELDING THE WASHERS AND SHEET METAL TO THE BAR JOISTS AFTER EMPLOYEE #2 FINISHED TACK WELDING THE PROCESS WAS STARTED OVER. EMPLOYEES HAD ABOUT 25 OR 30 SHEETS LAYED OUT (UNSECURED-NOT TACK WELDED). EMPLOYEE #1 PICKED UP TWO SHEETS OF CORRUGATED SHEET METAL, AND EMPLOYEE #2 PICKED UP TWO SHEETS ALSO, EMPLOYEE #1 HAD GONE ABOUT 30' FROM THE BUNDLE WHEN HE STEP ON AN UNSECURED SHEET WHILE TRYING TO GET A GRIP WITH HIS FEET THE PIECE OF SHEET METAL SLID OFF BARR JOISTS CAUSING HIM TO FALL THROUGH THE OPENING 21'10" TO CONCRETE FLOOR.