Sarah Sassoon Guyard-Guillot, 31, reportedly slipped out of her safety wire during a performance of Ka at MGM Grand. The spokesperson said the cause of death has not been determined and that the incident occurred at the MGM Grand showroom, but said further details were not immediately available. The Sun reported that the incident -- which marks the first reported onstage death in the 30-year history of Cirque Du Soleil -- occurred during Ka's closing Final Battle scene. Guyard-Guillot reportedly slipped out of her safety wire and fell at least 50 feet down into an open pit, out of the audience's line of sight and below the performers. Audience member Dan Mosqueda told the Sun that the performer was being hoisted up the side of the stage and then just plummeted down. Initially, a lot of people in the audience thought it was part of the choreographed fight. But you could hear screaming, then groaning, and we could hear a female artist crying from the stage.