Abstract: On March 17, 2010, Employee #1, a foreman, of Mayta & Jensen, was working on the 13th floor in the mechanical room on an extension ladder approximately 8 feet high. He was holding a grey trash can directly above his head with one hand and was holding onto the ladder with his other hand. Employee #1 was holding the gray trash can to catch the slurry which was being generated as the subcontractor, Jamco, was coring an 11 inch hole directly above Employee #1 on the roof. As the subcontractor was coring, the 11 inch concrete core fell into the grey trash container which Employee #1 was holding up with one hand causing Employee #1 to fall backwards off the ladder onto the concrete floor. The right shoe of Employee #1 came off during the fall. Employee #1 was yelling after he fell and the subcontractor on the roof and other subcontractors on the 13th floor came to see what was happening. The Federal Reserve Bank of San Francisco police then showed up. Paramedics were called. Employee #1 was able to walk down to the 12th floor and then took an elevator down to the ground floor. Employee #1 then walked out to the Federal Reserve Bank of San Francisco parking lot and was met by paramedics who had just arrived. Employee #1 was then taken via ambulance to San Francisco General Hospital emergency room. The following day, on March 18th, 2010 Employee #1 was transported via ambulance to Kaiser Hospital in Oakland, CA. Employee #1 sustained a L4 burst fracture and a laceration on his right foot from the fall and was fitted for a back brace and was released from the hospital on March 22nd, 2010. No one witnessed the accident.