WHILE EE WAS WALKING FROM SHOP AREA TO MIDWAY BUILDING HE STEPPED ON A LARGE STONE CAUSING HIM TO TWIST FOOT. HE DIDN'T REPORT ANYTHING WRONG & TOOK 2 PERSONAL VACATION DAYS W/O TELLING ANYONE WHAT HAD HAPPENED. 3 DAYS AFTER THE INCIDENT HE WENT TO THE HOSPITAL TO FIND THAT THE FOOT WAS BROKEN. ON MON. (5 DAYS LATER) HE CAME TO THE PLANT TO TELL US WHAT HAD HAPPENED. NO WITNESSES.