EE WAS CHANGING WEAR PLATES IN SAND SCREW. HE CUT BOLT HEADS OFF WITH TORCH AND WAS ATTEMPTING TO DRIVE THEM OUT WITH A HAMMER. HE WAS BRACING HIMSELF WITH HIS LEFT HAND AND WHEN HE SWUNG THE HAMMER TO KNOCK THE BOLTS OUT OF ONE WEAR PLATE, IT GLANCED THE OTHER AND HIT HIS THUMB.