No one was inside the store at the time the three-alarm fire broke out Sunday night at "Buck N Up" on 646 Nye Avenue.
Firefighters from 18 departments responded to the blaze.
The doors were locked and security gates were in place, which made initial access difficult.
The roof of the building collapsed during the early morning hours.
One firefighter suffered minor injuries but was treated and released.
The cause of the fire is under investigation.