Coroner's officials said Sarah Guillot-Guyard, 31, was pronounced dead at a hospital late Saturday night after falling about 50 feet from the show's stage during a production of "Ka" at the MGM Grand.
"I am heartbroken," Cirque du Soleil founder Guy Laliberte said in a statement. "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."
The incident was the first stage casualty in the company's 29-year history, according to Cirque spokeswoman Renee-Claude Menard.
Witnesses told the Las Vegas Sun that the accident occurred during a fight scene near the end of the production, which combines acrobatics with martial arts and puppetry and tells the story of twins on a heroic quest.
Visitor Dan Mosqueda of Colorado Springs, Colo., said the woman was being hoisted up the side of the stage when it appeared that she detached from her safety wire and plummeted to an open pit below the stage.
"Initially, a lot of people in the audience thought it was part of the (show)," he told the Sun. "But you could hear screaming, then groaning, and we could hear a female artist crying from the stage."
The show momentarily continued, then stopped. Minutes after the accident, a recorded announcement informed audience members that refunds or vouchers to future shows would be offered, and the crowd was dismissed.
Clark County coroner's officials say they expect to rule on the official cause of death Tuesday. Cirque officials are working with authorities investigating the accident and have offered their full cooperation, Laliberte said.
Menard said she could confirm that Guillot-Guyard didn't slip out of her harness, but couldn't provide additional information about the incident.
Guillot-Guyard, a mother of two, had been with the original cast of "Ka" since 2006, and had been an acrobatic performer for more than 20 years, according to Cirque officials. Born in Paris, she is also listed as the head coach at Cirquefit, a program that offers acrobatic fitness classes for children.
On a memorial website in her honor, commenters thanked her for inspiring their children, recalled her "infectious laugh" and poured out their condolences in English and French.
The MGM Grand also issued a statement concerning the accident.
"Our company is deeply saddened by the loss of one of the talented KA artists Saturday night," it reads. "The thoughts and prayers of our employees are with the performer's family, the cast of KA, and the entire Cirque family during this difficult time."
The accident occurred while Cirque's top executives, including president Daniel Lamarre, were in Las Vegas to celebrate the premiere of "Michael Jackson One" at Mandalay Bay.
On Wednesday night, a performer in a preview performance of that show suffered a mild concussion after missing the protective pad below an act and landing on the stage. That artist is expected to return to the show.
Montreal-based Cirque du Soleil was established in 1984 and now includes more than 1,300 artists, according to its website. "Ka" is one of 20 shows playing around the world this year - eight of which are based in Las Vegas.
No reopening date has been set for "Ka," Menard said.