Abstract: On March 8, 2011, Employee #1 was working for his employer, a general contractor that self-performed steel erection on a new self-anchored suspension span of the Bay Bridge. A temporary steel frame and several floors were erected around the permanent tower to provide platforms for its construction. The floors were made of many sections of metal bar grating. Some floor grates and supporting beams contacted each other by a couple of horizontal inches. The employer required the grates to be secured by wire, clamp, or weld. A floor at the 119-meter-level was erected around March 4, 2011. At approximately 2:20 p.m. on March 8, 2011, two ironworkers, Employee #1 and a coworker, working on that level were standing on a triangular piece of bar grating that had a 74-inch base and 36-inch height. The iron workers were unaware that it was not secured, and they did not have any form of fall protection. No signs or barricades were placed to warn of the danger. A crane was hoisting a large metal "fagade" structure, while the two ironworkers worked to get it into place on the tower above the grated floor. The two ironworkers were removing a long piece of angle steel, when the triangular piece of bar grate flooring came off its supporting beams and fell. Employee #1 fell through the opening previously occupied by the grate. He fell approximately 16 feet, 0.5 inches onto the metal bar grating floor on the 112-meter platform. The crane set the "fagade" piece down on the temporary floor, while various workers responded to the accident. Employee #1 sustained two dislocated shoulders and a broken ankle, for which surgery was required. He was hospitalized for a total of nine nights. The San Francisco Fire Department reported the accident to Cal/OSHA at 6:21 p.m. on the same day, and the employer reported the accident at 6:43 a.m. on the next day.