EE WAS OPERATING A CAT D9L DOZER RECLAIMING THE OUTSLOPE ON THE MTR MINE. HE WAS PUSHING DIRT & ROCK UP THE SLOPE AND AS HE BACKED DOWN THE SLOPE HE RAN OVER SOME ROCKS. SHORTLY THEREAFTER HE STARTED EXPERIENCING PAIN IN HIS LOWER BACK, MOST LIKELY DUE TO REPEATED TRAUMA.