Abstract: Employee #1 was standing on a 4,700 lb bundle of metal roof decking that had just been landed on top of a steel structure. The bundle of decking was resting on four open-frame bar joists that had not been secured to the structure. Employee #1 unhooked the nylon chokers and discovered that one of them was caught between the load and one of the bar joists. He could not shake the choker loose so he took the other choker and cradled it around the east edge of the load and signaled to the crane operator to lift the load. The operator lifted the load about 1 or 2 in. on the east end, raising it off three of the four bar joists. The fourth bar joist buckled under the load, causing a chain reaction in which the second and third bar joists also buckled. Employee #1 was killed when he fell 30 ft to the ground and was struck by the bundle of roof decking after it slipped out of the sling.