THE EE STATED THAT HE WAS HELPING TO UNLOAD BAGS OF ROCK DUST. HE UNLOADED 4 PALLETS OF DUST OFF A SUPPLY CAR WHEN HE STARTED TO HAVE PAIN IN HIS BACK. EE SAID THAT HE HAD PAST HISTORY OF BACK PROBLEMS. THE EE RETURNED TO WORK ON HIS NEXT SCHEDULED SHIFT. PLEASE NOTE: EE HAD A MRI ON 7-3-2001. HE DID NOT RETURN TO WORK AFTER VACATION PERIOD WHICH ENDED ON 7-9-01.