At 11:00 AM on 9/10/07 elevated CO reading was detected on monitor located in 6L return. Mine manager went to investigate & at 2:15 PM found hot spot in #000 @ survey station 17+06.24. Access was blocked by roof falls on both sides. We were instructed to load out fall to reach the burning material. Unsuccessful & on 9/11/07 permission was granted to build 3 seals around area.