THE INJURED EE WAS ROOF BOLTING ON UNIT 2. HE WAS WALKING OUT OF ROOM #1 AND A PIECE OF ROOF ROCK FELL FROM BETWEEN THE ROOF BOLTS, SCRAPING DOWN BOTH LOWER LEGS AND LANDING ON HIS RIGHT FOOT. THE INCIDENT CAUSED CONTUSION/ABRASION TO BOTH LOWER LEGS AND CONTUSION TO THE RIGHT FOOT. THE EE WILL BE INSTRUCTED TO ALWAYS CHECK ROOF AND RIB IN HIS WORK AREA AND AREA OF TRAVEL.