Abstract: Employee #1 and a coworker were tying rebar for a concrete pour on the roof of a 7 story building within 2 ft of the building's edge. A guardrail had been erected around the perimeter of the building; the midrail was 33 in. high. When Employee #1 had completed a tie and moved to begin another, he apparently tripped or somehow lost his balance. He slipped under the guardrail and fell 70 ft to his death. Had the midrail been erected at 21 in. or had Employee #1 been wearing a safety belt that was tied off to the structure, the fall might have been prevented. Weather did not appear to be a contributing factor. No one saw Employee #1 fall.