(NEWSER) – For the first time in Cirque du Soleil's three decades, a performer has been killed in a performance accident. Sarah Guyard-Guillot fell from a vertical stage Saturday night, witnesses say, plummeting some 50 feet into a pit. She was wearing a harness, but it appeared to have detached from its safety wire, the Las Vegas Sunreports. "Initially, a lot of people in the audience thought it was part of the choreographed fight. But you could hear screaming," said an audience member.