EE states that as he was getting into a scooter he felt/heard a ""pop"" in his right knee. Due to circumstances associated with this event, the mine operator is ""Red Lining"" this event as there may prove to be a non-occupational injury. Incident is under investigation. EE started losing work days on 10/17/2011,Per call11/22/11 with A.C. change missing date to 09/30/11.