Abstract: At approximately 12:56 p.m. on July 9, 2007, several employees were erecting a one-story precast unit. A crane had placed the second double tee concrete roof panel onto the wall supports. At this point of construction, there were two corner sections, consisting of two perpendicular walls, and two additional walls. The walls were on the north and south side of the building. Employee #1 was welding on the north end of the double tee. Employee #1 was anchored via a retractable lifeline to a safety eye on the first double tee. A coworker was working on the south side of the double tee and anchored to a second safety eye on the first double tee. Employee #2 had just shimmed the second double tee and was underneath this double tee in a man-basket. At this point, the coworker disconnected the rigging from the lifting eye which was used in the shimming process. The coworker communicated with the crane operator to cable up. The rigging consisted of a 4-leg wire rope sling. During the cabling up, one of the hooks on the rigging from the crane caught and snapped into the safety eye on the south end of the second double tee. This resulted in the south end of the second double tee being lifted, and pulled off the supports on the north. This, in turn, resulted in the second walls falling, and then the first double tee rupturing lengthwise. Employee #1 was on the north end of the double tee and fell with his tripod to the ground and was fatally injured. Employee #2 was underneath in the man-basket and suffered serious crushing injuries and was hospitalized in stable condition. The coworker was not injured because the section of the double tee where the safety eye to which he was connected did not fall. Employee #3 and Employee #4 were injured on the ground and were transported to the hospital, and treated and released.