EAST MAINS #9 ENTRY IN BY CROSS CUT. THE MMU 008 MINER FINISHED THE A CUT (CURTAINSIDE) AND THE B-CUT. THE OPERATOR WAS CLEANING UP THE A CUT AND JUST STARTED THE C CUT (CURTAINSIDE) WHEN SPAR KS FROM THE MINER BITS STRIKING THE SANDSTONE CAUSED A FRICTIONAL IGNITION THAT LASTED APPROX ONE TO TWO SECONDS.