Abstract: At 12:45 p.m. on August 17, 2006, Employee #1 was working with a crew that was repairing a chain going around a sprocket. The employee, with assistance from a coworker, was rolling up a chain over the drive sprocket. They both were working on portable ladders. The flight moved, the chain broke and struck Employee #1 in the chest. He fell from the ladder, approximately 3.5 to 4 ft, backwards, hitting the concrete floor with his buttocks. The coworker spoke to Employee #1 to see if he was okay, conscious, and if he had feeling in his fingers and toes. Other workers called for emergency medical services. The paramedics arrived and transported Employee #1 to Scripps La Jolla Hospital. Employee #1 sustained serious injuries including several fractures of the L1 and L2 vertebrae and was hospitalized.