A Contract employee was roof bolting in entry 3 when a rock fell out in front of the bolter ATRS. A piece of rock broke off of that rock that measured 34""x 4""x 1 to 2"" thick, and came back and struck ee on the ankle/leg area. The contract employee was transported to the medical facility and diagnosed with a hairline fracture of the fibula. EE started missing work on 1/31/17.