A four-alarm fire tore through the North Union Apartments in Midvale on Friday, July 31, forcing the evacuation of all 220 occupied units and burning for more than 12 hours as Unified Fire Authority crews fought to contain flames racing through concealed attic spaces.

No residents were seriously injured, though one was treated for heat exhaustion. Several firefighters suffered minor injuries, and one was caught in a partial roof collapse, called a mayday, but escaped uninjured, according to KUTV.

The four-story complex sits at 942 N. Union Ave., near Fort Union Boulevard on 900 East. UFA, which serves Cottonwood Heights and Holladay, dispatched crews to the scene at approximately 7:50 a.m. Friday after reports of smoke on the roof.

Fire started above the sprinklers

Investigators believe a mechanical failure in the attic likely sparked the blaze, according to Fox 13. Early reports that the fire started in a trash chute or was intentionally set have been ruled out.

"The building was sprinklered, but the fire started above the sprinklers," UFA Capt. Patrick Costin said. "That's why it got established and was able to run through the building quickly."

Costin described a gap of 3 to 6 feet between the roof and the top-floor apartments where the fire traveled undetected through concealed spaces, including the attic, trash chute, elevator shafts, and ventilation areas.

Defensive operations overnight

By early Saturday, UFA had shifted to defensive operations because conditions inside the building were too dangerous for interior crews, Gephardt Daily reported. Elevated master streams poured water onto the structure from above while crews deployed drones equipped with thermal imaging to locate hot spots.

The fire is one of the largest apartment blazes UFA has responded to in recent memory. It comes roughly two weeks after UFA battled four structure fires in 36 hours in the Holladay-Millcreek area, a stretch that prompted the agency to pre-call extra resources on any new working fire during summer heat.

Hundreds displaced

Evacuees were initially directed to Hillcrest High School, but when the school's air conditioning failed, the American Red Cross opened a new shelter at Fort Union Middle School at 615 East 8000 South in Sandy.

John Gregory, the father of a resident, told Fox 13 she called him from the shower as alarms sounded. Residents ran into the street thinking it was minor smoke, and Gregory said he doesn't believe anyone was able to retrieve belongings.

The North Union Apartments were built in 2022 and had a pre-fire market value of nearly $60 million, according to Salt Lake County records. A few pets remained unaccounted for as of Saturday.

What's next

Fire officials said it would likely be at least a couple of days, possibly several, before residents could return, pending investigator access and structural assessment. Midvale Mayor Dustin Gettel said the city set up a donation email at [email protected] for businesses wanting to help displaced residents. The American Red Cross can be reached at 800-RED-CROSS or redcross.org.