EE WAS IN THE PROCESS OF TURNING THE MG SETS WITH A SLING AND HOIST. AFTER HOOKING THE SLING TO THE MG SET, HE PUSHED THE UP BUTTON TO START THE HOIST REELING IN. HE REALIZED THE BUTTON WAS ST UCK AND BEFORE HE COULD GET UP AND GET TO THE BREAKER BOX, THE SLING CAME OFF OF THE SETS, CAUSING THE HOIST BLOCK TO POP UPWARDS AND SWING, STRIKING EE INT HE REAR OF THE HEAD. THIS RESULTED