Authorities say a private hangar under construction at Boise Airport collapsed, leaving three people dead and nine injured

In the evening of Wednesday, the privately owned hangar in Boise, the capital of Idaho, collapsed on airport property, injuring nine people and killing three, according to city officials.

The city's fire department reported on Wednesday that an investigation is being conducted to determine what caused the collapse of the metal structure, which occurred at West Rickenbacker and Luke streets on the edge of Boise Airport's airfield at approximately 5 p.m. MT.

Five of the nine injured survivors were in critical condition on Wednesday night and were being treated at hospitals, according to city officials. The identities of those slain and injured were not made public right away.

“There was a large-scale collapse of the building, the framework of the building. Aaron Hummel, operations chief for the Boise Fire Department, stated at a news conference on Wednesday, "I don't know what caused it, but I can tell you that it was a pretty global collapse that occurred," prior to the city releasing a death toll. “It was fairly catastrophic.”

According to Hummel, the building that was being built was not a city facility, and it had no bearing on airport operations. Hummel withheld information regarding the identity of the person building the hangar.

 In a statement released on Wednesday night following the press conference, Hummel stated that first responders "found a hectic scene and worked to secure and rescue victims."

The director of the airport, Rebecca Hupp, stated at the press conference that the construction was not an airport project.