Abstract: On November 26, 2017, Employee #1 and #2 were installing bar joists during the process of steel erection of the roof of the distribution center. The employees were connectors, and had installed two columns, two girder joists, and sixteen bar joists to complete two roof sections, referred to as bays. After installing the bar joists, four bundles of metal roof decking were lifted by the crane and placed perpendicular across the bar joists with two bundles per bay. A coworker was responsible for installing diagonal bridging per the design drawing. The coworker had not installed the diagonal bridging prior to the four bundles of metal decking being placed on top of the bar. Employee #1, who was responsible for welding the bar joist to the metal seat imbedded in the concrete tilt wall, had only welded on one side of the bar joist instead of both sides. The combination of the lack of diagonal bridging and lack of fillet welds being installed on both sides of the bar joist connected to the concrete tilt-up wall caused the bar joist to shift and roll from the weight of the bundles of metal decking being placed on them. The bar joist collapsed, killing Employee #1 and injuring Employee #2. It was also noted that there was a lack of certified fall protection training for employees working at or above six feet.