Abstract: Employee #1 was helping to align a set of metal stairs that were being installed. After the stair sections had been bolted and spot welded in place, a plumb bob revealed them to be approximately 2 in. out of line. A come-along was used to pull the stair platform into line, causing a metal flange to bend where it was spot welded. When the workers started to flatten the flange with a sledge hammer, the weld broke. As the come-along pulled the stairs backward, the bottom section of the stairs dropped away like a trap door. Employee #1 fell and struck his head on the flight of stairs below. He was killed.