EE STARTED SHOVELING DIRT IN OUR TUNNEL WITH COWORKER ABOUT 0745 AND ABOUT 10 MINUTES INTO SHOVLING HE HIT STEEL WITH HIS SHOVEL, SO HE REACKED DOWN TO PICK IT UP AND WHEN HE WAS TURNING TO PU T THE CHANNEL OFF TO THE SIDE OUT OF HIS WAY HE FELT SHARP PAIN IN HIS LOWER BACK ON HIS LEFT SIDE.