AT 8:17 AM SUFFICIENT AIR PRESSURE TO THE HOIST BRAKES COULDN'T BE MAINTAINED TO RELEASE THE BRAKES. THE AIR COMPRESSOR FAILED. A MINE EVACUATION WAS BEGUN IMMEDIATELY. THE AIR PRESSURE TO THE HOIST BRAKES WAS RESTORED USING AN AUXILLARY COMPRESSOR BY 9:20 AM. AFTER SKIP CHECKS, THE MINE EVACUATION WAS HALTED.