PRESTON ALERTED THE THREE HOUSE TO A REPORTED STRUCTURE FIRE AT THE SUBWAY RESTAURANT IN BRUCETON. ENGINE 320 GOES ON SCENE AND ESTABLISHES "BFS COMMAND" REPORTING NOTHING SHOWING. EMPLOYEES REPORT TO THE CREWS THAT EVERYONE WAS OUT OF THE STRUCTURE AND THAT THE WALL BEHIND THE TOASTER MACHINE HAD MADE A LOUD POPPING NOISE AND THE LIGHTS STARTED FLASHING IN THE STORE. CREWS CHECKED OUT THE ELECTRICAL SYSTEM AND THE WALLS USING THIER THERMAL IMAGING CAMERA BUT COULDNT LOCATE ANY FIRE OR HEAT. COMPANY THREE TERMINATED BFS COMMAND AND RETURNED TO QUARTERS