Abstract: On January 19, 2010, Employee #1 was working with a crew that was installing a steel sheet metal box header between two steel stud walls in a commercial building under construction. The two walls were located 25 ft apart. The box header was 5.5 ft by 5.5 ft by 25 ft. The box was being installed 12 ft above the floor. Employee #1 was standing on the fifth rung of an 8 ft A-frame ladder next to one wall. A coworker was on a rolling scaffold next to the other wall. Two other coworkers handed the box up to Employee #1 and the other worker on the scaffold. The coworker working on the end with Employee #1 climbed another A-frame to place vice clamps on the box as a temporary connection to the wall. Employee #1 and the coworker working with him had difficulty getting the box into the right position due to a hanger wire protruding from the ceiling. The coworker pushed the wire and Employee #1 tried to push the box into place. Employee #1's ladder tipped over. He and the box fell to the concrete floor. Employee #1 sustained four fractured ribs, a fractured collar bone, and lacerations to his head and thumb. Employee #1 was hospitalized for two days for treatment of his injuries.