EMPLOYEE WAS OPERATING AN OPEN TOP DIESEL POWERED PERSONNEL CARRIER. AS HE PASSED BY THE #20 CROSSCUT OF THE MAINS SOUTH TRAVEL WAY, A PIECE OF ROOF ROCK FELL FROM BETWEEN THE ROOF BOLTS, STRI KING HIM JUST BELOW THE LEFT EYE. THE INCIDENT CAUSED A LACERATION THAT REQUIRED SUTURES. EMPLOYEE WILL BE INSTRUCTED TO ALWAYS CHECK CONDITIONS IN HIS WORK AREA.