Abstract: At 1:00 p.m. on September 23, 1988, Employee #1 and a coworker, a mason laborer, were on a scaffold that had been erected on the wood floor of a second-story stairwell of a townhouse under construction. Employee #1 was 9 ft from floor level as a load of block was being placed on the scaffold. A wood joist end in the floor beneath the scaffold cracked and gave way, causing the scaffold to fall over. Employee #1 sustained a scalp wound and back injuries. A 5 ft house masonry wall was knocked over the wood floor and was damaged. The carpenters who constructed the wood floor had failed to support one end of the 2 by 10 by 123 ft wood joist. The end had only been stacked and was not supported by a metal joist support bracket.