A PIN IN AN EXCAVATOR'S TRACKS WERE BEING DRIVENBACK INTO PLACE WITH A SLEDGE HAMMER. A SMALL SLIVER OF THE PIN CHIPPED OFF AND STRUCK THE EE IN THE LEFT CHEST. THE SLIVER PENETRATED THE SKIN ROUGHLY A 1/4"" AND CAME BACK OUT, THE EE WAS GIVEN SEVERAL STITCHES AND RELEASED TO FULL DUTY.