Abstract: On July 21, 2011, an employee, who was the Project Manager for Danco Waterproofing Corporation, went to a construction site at a San Francisco State University parking structure. The work project involved seismic retrofitting of the parking structure. The employee's crew was to waterproof the vertical wall of an elevator shaft. The area adjacent to the elevator shaft had been excavated to install waterproofing fabric. The excavation was approximately 44 inches deep and 4.5 feet wide. Earlier that morning, the General Contractor, C. Overaa & Co., had been collecting scrap lumbers on a platform made out of a 0.75 in. thick plywood board supported by two 7-foot planks (1.5 in. by 9.5 in.) placed over the excavation 3 to 4 feet apart. At the time the employee and crew began work, the scrap lumbers and the board had been removed but the planks remained over the excavated area. At approximately 7:45 a.m., the employee stepped on one of the two planks to cross over the excavated area. The plank broke, and the employee fell approximately 4 feet. He landed on his right heel, and his right heel bone shattered. Paramedics transported him to Kaiser in San Francisco, where his broken foot was immobilized for later surgery, which was performed August 8, 2011. Investigation determined the cause of the accident was a single, damaged plank used to cross over the excavation. The employer was cited with one General Citation. T8 CCR 1624(a) requires runways or ramps for the use of workers to be at least 20 inches wide and to be properly supported as to avoid deflection and springing action. The general contractor had provided a dirt ramp and ladder for access to the excavated area and therefore was not cited.