A fire inside a hopper at a large commercial warehouse prompted a brief evacuation Friday afternoon as Turlock firefighters fought to keep the fire from spreading to other areas of the structure. The Turlock Fire Department was dispatched to the 100 block of South Walnut Road around 1 p.m. Friday to respond to a commercial fire alarm. The first crews to arrive from Squad 32 and Truck 31 were told by employees there was a smoldering fire in an industrial bag-house filter.