Abstract: On July 7, 2003, Employee #1 was performing plating work on a building of a multi-unit apartment complex under construction. The activity consisted of installing 2-inch by 4-inch pieces around the perimeter of the concrete deck and around the floor openings in the deck. The employee was standing on the concrete deck with one foot down approximately 12 inches in a 4-foot by 4-foot floor opening, and the other foot on the deck. The foot in the opening was on plywood that was supported by vertical shores underneath the concrete deck. He was reaching down to pick up tools when he heard and felt something hit the vertical shores, causing the plywood to move. Before he could get his foot out of the opening, the plywood fell from under his foot causing him to fall through the opening approximately 8 feet to the concrete floor. He was transported to Los Robles Hospital in Thousand Oaks, where he was hospitalized for 13 days and underwent surgery on his leg.