BOISE — More than a dozen emergency vehicles responded to a large fire at the Idaho Youth Ranch warehouse on Monday afternoon.

The three-alarm blaze burned at the warehouse location at 5465 W. Irving St. in Boise.

“As you can see, we had a pretty extensive fire here,” said Aaron Hummel, operations and EMS division chief for the Boise Fire Department, during a media briefing near the fire site. He said the blaze was called in just after 2 p.m.

A tower of brown-gray smoke from the site was visible over the Treasure Valley after 2:15 p.m. and into the afternoon. As of 2:45 p.m., no injuries to civilians or firefighters had been reported, and the fire had been contained to the original warehouse building at the site, Hummel said.

The fire was upgraded to three alarms due to the warm weather and the potential for firefighters to suffer heat-related injuries, Hummel said.

Idaho Youth Ranch CEO Scott Curtis confirmed there had been no injuries reported. The site is the “master distribution center” for the thrift store’s operations where goods are processed and distributed to stores, he said.

“This is a critical piece to our mission,” Curtis said. “It’s the way the community donates and supports all the work we do,” he said, adding that the organization’s next step will be to assess the damage and determine “what it’s going to take to be back and running full speed.”

Additional administrative roles such as development and marketing are housed at Irving Street site, too, Curtis said. As of Monday afternoon, all of the organization’s mission programs, including services to youth and families, were still running, he said.

Though the fire department alerted people to the emergency through the county’s Code Red system, the warehouse is located in a commercial area where no homes were affected, Hummel said.

Crews were also working in the adjacent warehouse to prevent it from catching fire, Hummel said. Initially, crews also prioritized protecting propane gas tanks near the site, he said.

Hummel said the Boise Police Department and the Boise Fire Department’s Fire Prevention Bureau will be conducting an investigation to determine the cause of the fire.

The fire appeared to have originated in a warehouse that had largely collapsed Monday afternoon, Hummel said. Crews were working to douse the flames from the outside.

“Because of the advanced fire conditions fire crews are attacking the fire from the outside,” the Boise Fire Department tweeted. “Drivers are asked to avoid the area.”

Hummel said that he expects crews to work “well into the night” to extinguish the fire.

The Idaho Youth Ranch is a nonprofit organization that “offers emergency shelter, residential care, youth and family therapy, job readiness training, adoption services, and more for kids and their families,” according to its website.

The organization also operates 25 thrift stores statewide.

Recently, the Idaho Youth Ranch raised more than $27 million in private funds to construct a new psychiatric residential treatment facility in Canyon County.

Video from the fire and media briefing is available here.Madison Guernsey and Sydney Kidd contributed to this report.