Abstract: At approximately 8:00 a.m. on December 05, 2009, Employee #1 was working at the Elvis Cirque Du Soleil Theater at the now Aria Resort & Casino. During the course of the shift, Employee #1 and his crew had been instructed to do touch-up to the seating that were damaged during the course of installation. After the shift had ended, Employee #1 and some of his crew members exited the theater via stage left in order to reach the stage left elevator. After reaching the elevator, Employee #1 remembered that he had left his jacket in the seating area of the theater. Employee #1 was crossing from stage left to stage right when he fell through an opening in the stage. A stage lift, C5, had been lowered 27 ft to the basement level leaving a large opening. The C5 lift measured 75 ft long with a width of 18 ft. No guardrails or other methods of fall protection had been placed near the stage lift to prevent employees from accessing the area. After the accident, Employee #1 was assisted by other employees of the theater and hotel security first responders. He was then transported to University Medical Center, where he received medical treatment for his unspecified injuries and was hospitalized.