According to the Unified Fire Department, the fire broke out in a second floor mechanical room.
Firefighters had to cut a hole in the roof of the complex to completely extinguish the fire.
The complex had four units and all of them have been evacuated for the night. The Utah Red Cross is helping the family with arrangements.
Damage to the complex is estimated at $50,000.
Watch ABC 4 news at 10 p.m. to find out all the latest details.