Eight women were injured in a freak accident during an acrobatic circus performance in Providence, Rhode Island this Sunday. Thee of the performers remain in critical condition, USA Today reports. The women were performing their routine “Hair Hangers” act in the Ringling Bros. and Barnum & Bailey circus show on Sunday, when one of the clamps holding together the complex aerial rig for their routine failed. The rig, along with the acrobats, then crashed to the ground, injuring about a dozen people in the process.

"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. The investigation is continuing.

More: Circus Act Ends In Horror As Performers Crash To The Ground

This is the short version, but a full investigation is also being conducted by the Occupational Safety and Health Administration in cooperation with city and state officials, Pare said in a statement. Apparently it isn’t an investigation into the acrobats’ working conditions or the legal standing of the circus, since the establishment had all the permits required to operate the rig. A medical response team was also on hand to administer first aid. In addition, all the injured were conscious when taken to hospitals. Fire and police arrived at the scene and aided an evacuation of the crowd of more than 3,900 people.

"Clearly something went very wrong with this apparatus," Stephen Payne, a spokesman for Ringling Bros. and Barnum & Bailey circus, adding that the fate of future shows would be determined by an investigation that the circus had begun. "The safety of our performers is the No. 1 priority."