The fire broke out around 4 p.m. Monday at 2915 Glen Dr. near Pacific Street.
No one was injured, but the building was so badly damaged that residents haven't been able to return to retrieve their belongings.
City official Kathleen Vincent said residents will have to wait a while longer before they get access.
"Our fire crews will remain on scene and complete their investigation. After they've completed their work, they release the building to a restoration company and then it would be that restoration company that provides access to the building once it's safe to do so," Vincent told CBC News.
The cause of the fire is still under investigation.