About a dozen people have been injured after a building collapsed in the grounds of the airport in Boise, Idaho, officials said.
Boise Fire Department operations chief Aaron Hummel said a steel-framed hanger collapsed about 5pm on Wednesday and everyone who had been at the site had been accounted for.
He would not comment on the condition of those injured or say whether anyone had died while officials were working to contact family members.
“It was a very chaotic scene,” he 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”.
He said some of the victims were on a hoist or other elevated platform at the time the structure fell and confirmed a crane also collapsed in the incident.
Boise Airport operations were not impacted, officials said.
The collapse happened next to Jackson Jet Centre, which offers private airplane charters and maintenance, and city permitting records show permits to build a jet hangar for the company.
Jackson Jet Centre chief executive Jessica Flynn said in a statement their “hearts go out to everyone affected by this horrific event”.
“We do not know exactly what caused the hangar collapse,” she said. “Our focus now is on supporting our team and partners during this difficult time.”