Employee was in the process of untangling a miner cable and water line when he tripped and twisted his left knee. He was taken to a local hospital; x-rays were performed with negative results. Injured employee returned to work and continued to work, but pain worsens. On 6-28-2011 a MRI was performed. On 7-11-11 the specialist removed him from work, to repair the ACL of his knee.