"We have identified a clamp that snapped that held them to the rafters, and it failed," Providence Public Safety Commissioner Steven Pare told WPRO-AM. Three of the acrobats are still in critical condition, but none of the injuries appear to be life-threatening, the Associated Press reports.
"Unfortunately this particular clamp failed," Pare said. "It snapped off. We have it, we're analyzing it, we're seeing why it happened to ensure it doesn't happen in the future. That's all part of our focus." The performers fell 25 to 40 feet onto another dancer on the ground.
The act was part of the "Legends" show of the Ringling Bros. and Barnum and Bailey Circus, during which the performers hang "like a human chandelier" using their hair. The accident was witnessed by an audience of about 3,900 people, which included many children.