Three people were killed and another nine injured — five of them critically — after a hangar under construction at Boise Airport suffered what officials called “a catastrophic collapse.”

The privately owned steel-framed structure, located on the edge of the airport property in Idaho’s capital city, came crashing down early Wednesday evening, Boise Fire Department Operations Chief Aaron Hummel told reporters. When emergency personnel arrived at the airport shortly after 5 p.m., they discovered “a hectic scene” and raced “to secure and rescue victims,” he added.

Some of the victims were on a hoist or elevated platforms at the time the hangar fell, requiring first responders to use specialized rescue tactics.

A crane also toppled over in the “large-scale collapse,” Hummel said.

“I don’t know what caused it, but I can tell you it was a pretty global collapse,” he told reporters, further noting Boise Airport operations were not impacted.

Everyone on site at the time has since been accounted for, city officials noted.

The hangar involved was owned by Jackson Jet Center, a company that sells private airplane charters across the United States and Canada, according to its website. It boasts private hangar space and pilot service facilities at both Boise and Phoenix airports. In a statement to KIVI, Jackson Jet confirmed the collapse “occurred just west of our existing Jackson Jet Center at our new 39,000-square-foot steel hangar under construction, where dozens of dedicated people were working on site.”

The $6.2 million project was slated to include the construction of a concrete foundation and a metal building. According to Boise city records, the contractor Big D Builders had obtained permits for the job.

“Our hearts go out to everyone affected by this horrific event, especially those with loved ones on site when this tragedy occurred,” Jackson Jet said. “We’re immensely grateful for the rapid and professional response of Boise Fire, Boise Police and Ada County Paramedics along with the expert care of our area hospitals.”

It added: “We do not know exactly what caused the hangar collapse. Our focus now is on supporting our team and partners during this difficult time.”

As of early Thursday morning, none of the victims has been identified.

An investigation into what caused the collapse is underway. Representatives with the Occupational Safety and Health Administration also responded to the scene.

With News Wire Services