Abstract: On December 9, 2010, Employee #1 was a connector employed by a steel erector subcontractor. He was part of a four person work crew that performed steel erection activities during the new construction of a school. The four person work crew performed hoisting, rigging, and setting several steel bar joists as roof trusses. The crew used a truck-mounted crane with a 23 ton capacity to perform this work. The weather was clear and dry with little or no wind. The crew set one end of the bar joists on a concrete block wall. The crew put the opposite end of the bar joists above the top of the perimeter concrete block walls. There was a concrete slab floor between the walls. The bar joists were approximately 38.5 ft long, 18 in. high and 6 in. wide. Each bar joist weighed approximately 500 lb. The crew rigged the bar joists with a single choker synthetic web sling attached to the approximate center of the bar joists and also to the clevis hook on the headache ball on the running line of the crane. Employee #1 stood on top of an interior concrete block wall that was approximately 12 in. wide. Employee #1 wore a full body harness and lanyard. Another employee, also a connector, sat on top of an interior horizontal steel I beam opposite Employee #1. The second connector gave hand signals to the crane operator. The second connector wore a full body harness and a lanyard. His lanyard was tied off to an adjustable "beamer bar" attached to the horizontal steel I beam. Both Employee #1 and the second connector were approximately 18 ft above the concrete slab floor. The crane lowered one of the bar joists between Employee #1 and the second connector. The bar joist struck Employee #1 and knocked Employee #1 off of the concrete block wall. Employee #1 fell approximately 18 ft to the lower level concrete slab. Employee #1 suffered extensive head injuries including a concussion and body trauma. Employee #1 died from these injuries.