A fire that tore through a Midvale apartment complex Friday, forcing hundreds of residents from their homes, was likely caused by a mechanical issue, officials said.

The blaze began around 8 a.m. and quickly grew into a four-alarm fire that drew eight crews.

Firefighters spent the night pouring water on the building, and by Saturday morning, they had the fire under control. Crews continued working to extinguish hot spots, said Nate Cochran, a spokesperson for Unified Fire Authority.

Crews are still assessing whether the building is safe to enter before investigators can take a closer look inside, Cochran said Saturday. However, he said officials have ruled out arson and narrowed the cause down to a mechanical problem, though they’re still trying to figure out exactly what happened and how it started.

Investigators also ruled out a trash chute as a possible cause, he said.

All 223 units at North Union Apartments evacuated Friday, leaving hundreds of residents displaced and waiting for word on when they can return home.

“Hopefully in the next couple days we can let people in to at least grab their belongings and their cars as well,” Cochran said, adding that many residents’ vehicles remain in the building’s underground parking garage.

The American Red Cross of Utah opened an emergency shelter Friday night at Union Middle School, and is asking for donations to help those displaced. The organization said on X it is seeking donated food, clothing and household items, as well as money to help residents replace essentials like medications and eyeglasses.

Midvale city is also turning to local businesses for help, asking them to donate discounted hotel stays, grocery store and gas gift cards, and other services for displaced residents.