Shock as Cirque du Soleil performer Sarah Guyard-Guillot plummets 50ft to her death in Las Vegas

Sarah Guyard-Guillot, a mother of two, appeared to slip free of the safety wire during a performance of Ka in Los Vegas

Sarah Guyard-Guillot, left, fell after slipping on a safety wire on Saturday. (AP)

A Cirque du Soleil performer plummeted 50ft to her death, after slipping during a performance of Ka in Las Vegas.

Sarah Guyard-Guillot fell towards the end of the production on Saturday night at the MGM Grand, according to witnesses quoted in the Las Vegas Sun.

Members of the audience reported that Ms Guyard-Guillot, a mother of two, appeared to slip free from her safety wire and fall into a pit below performers.

The show momentarily continued then stopped when it became clear that she was injured. Emergency services were called and a recorded announcement dismissed the audience, who were informed they could expect refunds or vouchers for up-coming shows.

Guyard-Guillot, 31, was pronounced dead at 11:43pm Saturday at University Medical Center.

Dan Mosqueda of Colorado Springs said Ms Guyard-Guillot was being pulled up the side of the stage when she seemed to slip from her safety wire and plummet into an open pit below.

“Initially, a lot of people in the audience thought it was part of the [show],” he told the Las Vegas Sun newspaper. “But you could hear screaming, then groaning, and we could hear a female artist crying from the stage.”

Cirque du Soleil founder Guy Laliberte said he was “heartbroken” following the incident. In a statement he said: “I wish to extend my sincerest sympathies to the family. We are all completely devastated with this news. We are reminded, with great humility and respect, how extraordinary our artists are each and every night. Our focus now is to support each other as a family.”

Ms Guyard-Guillot, who was born in Paris and had performed with the original cast of Ka since 2006, and had been an acrobat for more than 20 years.

Her death is the first fatal accident during a live performance in the show's 30-year history.