The EE was injured when a rock measuring 13"" W X 13.5"" T X 17"" L fell from the rib near his postion and caught his left ankel. The section is pillaring and the EE had just started taking a miner cut with the cont. miner out of the left hand pillar. Shuttle car circuit breaker kicked & EE stated he would eat while breaker was put back in SC. Eating lunch when rock rolled of rib.