A hangar under construction on the grounds of the airport in Boise in the U.S. state of Idaho, collapsed on Wednesday, injuring about a dozen people, officials said. Authorities responded at about 5 p.m. to a private business located at the Boise Airport for a steel framed hangar that collapsed, Boise Fire Department Operations Chief Aaron Hummel said during a news briefing. Everyone who had been at the site had been accounted for as of Wednesday evening, he said. Hummel wouldn't comment on the condition of those injured or say whether anyone had died. He said officials were first working to contact family members. “It was a very chaotic scene,” Hummel said, describing the incident as a “large-scale collapse” of the framework of the building. “I don’t know what caused it, but I can tell you it was a pretty global collapse,” he said, calling it “catastrophic.” Boise Airport operations were not impacted, officials said. Hummel said some of the victims were on a hoist or other elevated platform at the time the structure fell, and that required some specialized rescue efforts. He said a crane also collapsed in the incident. Authorities are investigating what caused the collapse.