Abstract: Employee #1 was part of a three-man crew that was erecting exterior, pre-framed walls in a private residence. The residence's entire basement was poured and finished. On the first floor, the floor was fully decked except for the stairway opening, and all of the framed walls were in place. On the second floor, the floor was fully decked except for the stairway opening and one section of framed wall had been erected. A second section of framed wall had been built and was lying on the deck. Employee #1 bent over, slammed the claw of his hammer into the framed section, and started to pull on the wall to move it into position for tipping up into place. He was moving backward when the claw suddenly slipped out and Employee #1 stumbled a few steps back and into the second floor opening. He fell approximately 18 ft, traveling through the first floor opening and landing on the concrete floor in the basement. He sustained severe head and arm injuries, and was transported to Lakes Region General Hospital.