EE AS INSTALLING A 5FT RESIN TENSION BOLT IN THEFACE OF THE NO1 ENTRY ON C MAINS 002-0 MMU. EE WAS USING A 3FT DRILL WRENCH TO SPIN & TORQUE THE BOLT AFTER TORQUEING THE BOLT HE LEFT THE HE AD DOWN THE WRENCH STUCK THE BOLT & CAME OUT OF THE DRILL POT & STRUCK EE IN THE FOREHEAD CAUSING A LACERATION REQUIRING 8 SUTURES TO CLOSE. EE STARTED OFF WORK ON 4/17/00 RETD 4/24/00