Abstract: On October 15, 1985, Employee #1 and a coworker were on a scaffold installing drywall in the stairway of a building under construction. The scaffold was constructed so that a 4 ft by 8 ft by 1/2 in. piece of plywood was resting on three pieces of lumber that were supported on one end by the second floor landing and on the other end by a self-propelled mobile scaffold located on the stairway landing between the first and second floors. Because the piece of plywood could not be positioned properly in the stairway for them to complete the drywall installation, the employees dismantled the scaffold and removed the mobile scaffold from the landing. In its place they put a 2 in. by 12 in. by 14 ft piece of lumber; one end was supported by the second floor landing and the other end by a 4 in. wide ledge on the west wall of the stairway. The ledge was 6 ft 5 in. above the landing between the first and second floors. The plank was supported approximately in the center by two 2 ft by 4 in. metal studs, one of which was attached on each side of the plank and extended to the landing. While Employee #1 was walking on the plank to position two pieces of drywall material, the plank gave way from its support on the ledge. Employee #1 fell to the concrete landing between the first and second floors, striking his head on the steps. He was hospitalized. The plank did not have any guardrails and no ppe was in use. Employee #1 had 19 years of experience as a drywall installer.