Face equipment was being recovered from the completed Longwall Panel No. 13. The recovered longwall face equipment was being transported to, and set-up in, the adjacent 13A Headgate in preparation for mining the last panel of this three panel longwall district. The first longwall panel mined in the district was the No. 12 panel. The B West Mains was used as tailgate entries when Longwall Panel No. 12 was mined.
The active longwall gob area inby the recovery face was ventilated by the Lone Pine Fan. Also, the seals of three other sealed longwall districts were ventilated by the Lone Pine Fan. The seals of two mined out longwall districts in the B West Mains were not accessible because of poor ground conditions.
On January 28, 2000, at 9:10 a.m., a high carbon monoxide (CO) alarm occurred on the Conspec System sensor at the Lone Pine Return Fan. One management team was dispatched and traveled through the 13A Headgate to the back of 13 Headgate and the bleeder entries. A second team traveled from the Lone Pine West Slope into the bleeder entries across the back of the longwall gob area. At 12:55 p.m., the team encountered high levels of CO and low levels of oxygen at the 12 TG BEP, a bleeder tap at the back of the B West Mains. A fire was suspected and the mine was evacuated safely. Sampling was begun at the Lone Pine Fan.