Abstract: Employee #1 and two coworkers, all iron workers, were attempting to square a prefabricated section of stairway at approximately the 65 foot level of a new grain elevator headhouse. One coworker was working from above the stairway; Employee #1 and the other coworker were working directly below from a properly guarded walkway. The coworker who was above stated that he saw Employee #1 step up onto the intermediate rail of the walkway's guardrail to drive a bull pin below the stairway under the upper offside brace. As he leaned out to hit the pin, Employee #1's feet slipped off the intermediate rail and he fell over the top rail to his death. All three ironworkers were behind guardrails and all three were wearing safety belts and lanyards. Employee #1 had not tied off his lanyard to a secure object. Company policy requires the use of PPE. Failure to have and use it is cause for termination.