#3 Hdg., 6 to 7 x-cut. Mains North. The injured was working beside a roof bolter when a rock fell out between bolts in #3 Hdg 6 to 7 x-cut. The rock struck the individual in the back of the head, knocking him face first into the machine. The area was bolted with 6' resin bolts and employee was getting ready to install a 12' cable bolt.