Firefighters were called out to two fires at the Hill Country Village Plaza in the 14000 block of Highway 281N.
The first fire happened about 11:30 p.m. Friday and investigators believe that the fire was electrical.
The second fire happened about 2:30 a.m. Saturday.
The fire was on the roof of the building. Firefighters said there is no word on how the fire started but, arson is now investigating it.
The estimated damage to the building is $100,000.