WHEN PILLAR MINING IN THE NO.8 ENTRY ON C-3 PANEL. THE RADIO REMOTE CONTROLLED MINER WAS TAKING THE 1ST LIFT OFF OF THE BLOCK TO BE 2ND MINED. THE MINER WAS INTO THE BLOCK OF COAL APPROX. 20' WHEN THE MINE ROOF FAILED, ALLOWING THE MINING MACHINE TO BECOME ENTRAPPED BY THE ROOF ROCK FOR MORE THAN 1 HOUR. NO INJURIES RESULTED IN THE INCIDENT.