The fire was reported at about 1:35 a.m. at El Tapatio restaurant at 40 Golf Club Road, and was controlled by firefighters at about 3:40 a.m., Battalion Chief Dave George said.
Arriving firefighters "encountered a wall of flames and smoke upon their arrival because this fire had a stranglehold on the inside of this building," George said.
While fighting the blaze, a firefighter was injured, George said. The firefighter was part of a rapid intervention crew assigned to rescue other firefighters if they were in danger.
The firefighter collapsed outside the building, fell face first onto the cement and was knocked unconscious, according to George. He was transported to a local hospital where he has regained consciousness but is still disoriented, George said.
The fire caused between $1 million and $1.5 million in damage, and required the assistance of 33 firefighters to put it out in a little more than two hours, George said.
It was the second time the business has been destroyed by flames in the past three years. A three-alarm fire destroyed El Tapatio on Dec. 20, 2006.
George said it was "certainly unusual" and "almost unheard of" for the same building to be destroyed twice within such a short time, but said the fire appears to be accidental, according to an initial investigation. He said the cause has yet to be determined, but possibly came from an electrical source.
The restaurant is part of a strip mall on Golf Club Road, and all other businesses in the mall will be able to operate today, according to George.
Fire investigators will continue investigating the cause of the blaze and also what caused the injured firefighter to collapse, George said.