THE MINER CONDUCTED VISUAL AND SOUND VIBRATION METHOD ON TOP/ RIB AND HIS WORKING ENVIRONMENT LOOKED SAFE. WHILE STANDING BESIDE THE MINER, A PIECE OF RIB BLEW OUT WITHOUT WARNING, PUSHING THE EMPLOYEE TO THE PAVEMENT. THE PIECE OF RIB APPROX 8 IN THICK BY 4 FT WIDE BY 5 FT LONG LANDED ON THE EMPLOYEE'S LOWER LEGS AND FEET.