Abstract: A 50 FOOT LONG STEEL GIRDER, WEIGHING 3500 POUNDS, WAS HOISTED INTO PLACE BY A HYDRAULIC BOOM CRANE. ONE END WAS BOLTED THROUGH THE WEB TO A FLANGE THAT HAD BEEN WELDED TO A VERTICAL BEAM. TWO OF THE THREE 3/4 INCH BOLTS AND NUTS WERE INSTALLED. THE GIRDER WAS SUPPORTED APPROXIMATELY 12 FEET FROM THE OTHER END BY A VERTICAL COLUMN WHICH WAS SHIMMED ONE INCH OFF THE CONCRETE FLOOR BY TWO 7/8 INCH HIGH NUTS AND 1/8 INCH THICK WASHERS OPPOSITE EACH OTHER, AND 90 DEGREES FROM THE TWO HALF INCH BOLTS WHICH PROTRUDED FROM THE CONCRETE FLOOR. THE BOLTS WERE SET THROUGH 3/4 INCH HOLES IN THE BOTTOM PLATE. THE NUTS WERE WRENCH-TIGHTENED WITH ONE WASHER ON EACH BOLT. ONE IRONWORKER, WHO WAS STRADDLING THE GIRDER, HAD LOOSELY FITTED ONE OF TWO 3/4 INCH BOLTS AND NUTS TO SECURE THE GIRDER TO THE COLUMN. THE CRANE SUPPORT WAS SLACKED OFF. THE GIRDER WAS "SHAKEN" BY THE IRONWORKER TO SEE IF IT WOULD SUPPORT ITSELF. THE LOAD WAS THEN UNHOOKED BY A SECOND IRONWORKER STANDING MID-WAY ON THE GIRDER. AFTER THE LOAD WAS DISCONNECTED, EMPLOYEE #1 SUSTAINED SEVERE HEAD INJURIES WHEN THE COLUMN/GIRDER FELL APPROXIMATELY 20 FEET TO THE FLOOR. EMPLOYEE #1 WAS LEANING OVER TRYING TO CONNECT A SECOND BOLT WHEN THE BEAM FELL.