From a discussion with some underground miners at Upper Big Branch:
“No way was this explosion caused from methane build up on the cutting face. The machine would detect and shut down. Ventilation was the problem. Strata could have been cracked elsewhere, most likely in the floor as methane rises. There could be a worked out mine beneath that mine that built up over years with methane and leaked in. Accumulative MTR blasting around the mine could have cracked strata and allowed the methane to enter. The entire cliff strata at Sundial just let loose and buried the road 3-4 weeks ago, let’s not forget that. All these miners should have had methane detectors on them and they should have sounded an alarm. At least that’s supposed to be the case in a union mine.”
DISCLAIMER: We want to make note that this is opinion from a discussion with some miners from the area, and not an official statement from the mine, or Massey Energy.