MSHA briefs families about conditions at Upper Big Branch mine before deadly explosion

Mine Safety and Health Administration investigators met for the first meeting in four months with families of the victims of the Upper Big Branch mining disaster. MSHA laid out the circumstances leading to the volatile mix of methane, excessive coal dust and sparks from machinery that led to the explosion. Only family members of the 29 victims and their lawyers were admitted to the meeting, but several spoke anonymously with Howard Berkes of National Public Radio. "MSHA investigators were careful to say that they have not reached final conclusions and noted their final report is still 60 to 90 days away," Berkes writes.

MSHA investigators said they still were not certain of the source of the excess methane present in the mine on the day of the explosion, but noted the shearer -- a longwall cutting tool -- was creating more sparks than usual as it cut into coal and sandstone. The carbide-tipped teeth on the blade had been worn down to bare steel. "Those sparks would have been contained, cooled or extinguished by a system of water sprayers at the shearer but they were not working properly, as NPR has reported," Berkes writes. The faulty water sprayers also contributed to a buildup of coal dust which is an accelerant when it ignites.

"One of the government's experts told the families most of the mine was lined with excessive coal dust," Berkes writes. "At Upper Big Branch, without working water sprayers, the investigators said, the small methane ignition persisted. Floating coal dust fueled it and when it finally blew, the resulting blast was fed by coal dust spread throughout the mine, which explains an explosion that turned corners and killed along a two-mile path." Officials did not blame Massey Energy, the owner of the mine, during the Tuesday briefing but noted the company was "non-compliant" in multiple ways. Massey is expected to brief the families on its own investigation on Friday. (Read more)