An accident at a circus performance in Providence, R.I., over the weekend is still under investigation, but officials said Monday that it was caused by a broken carabiner.

“It was a single piece of equipment that failed,” Paul Doughty of the Providence Fire Department said during a news conference Monday. “It snapped.”

The accident occurred during a Ringling Brothers and Barnum & Bailey circus performance Sunday morning at the Dunkin’ Donuts Center in Providence. Nine performers were injured during an act that involved suspending people in the air. This video, captured by one of the nearly 4,000 people in the audience, shows the moment the apparatus collapsed:

An audience member's footage shows a circus apparatus falling to the ground with more nine acrobats still tethered to it. (Reuters)

Two of the performers were in critical condition, with others ranging from good to serious condition, the Boston Globe reported.

Ringling Brothers and Barnum & Bailey Circus said in a statement Monday afternoon that one of the nine performers who was taken to the hospital has been released.

“None of the injuries to the remaining performers are considered life threatening,” said the statement from Feld Entertainment, which owns Ringling Brothers.

Ringling Brothers canceled the remaining Providence performances scheduled for Sunday and Monday and said that the company will investigate what happened. In addition, the Occupational Safety and Health Administration is investigating.

The traveling circus is scheduled to head to Hartford, Conn., on Tuesday. Performances were still planned in Hartford from Thursday through next Sunday.