MSHA Agrees Lightning Likeliest Cause of Sago Blast, Plans New Rule on Seals

MSHA yesterday posted its extensive investigative report into the cause of the Sago Mine blast in January 2006 that killed a dozen miners and brought about the sweeping MINER Act reforms passed by Congress. The safety agency said it agreed with a state investigation and the mining company's contention that lightning was the most likely trigger of the methane blast, which is an explanation the United Mine Workers of America has disputed.

MSHA's chief, Richard Stickler, also announced the agency will take regulatory action on seals, which were implicated in this blast and another fatal one in 2006. MSHA already raised its 20-psi standard to 50 psi by emergency order. Stickler said MSHA is "aggressively pursuing regulatory action to require mine operators to take additional steps to protect miners from the dangers of explosions in sealed areas. We at MSHA extend to the families our deepest condolences for their losses and thank them for their patience during our investigation." The report, divided into several sections because of its length, is posted at www.msha.gov. MSHA said it contracted with Sandia National Laboratories to study whether energy from a lightning strike could travel underground, and Sandia's experts concluded energy from lightning could travel through the strata above the sealed area of the Sago Mine. "Sandia also determined that this energy induced on an abandoned cable was sufficient to ignite the accumulated methane in the sealed area where the explosion occurred," MSHA said. 20-psi seals were in place in the Sago Mine, as MSHA allowed at the time. MSHA investigators determined the force of the explosion exceeded 93 psi at the seals.

UMWA's international president, Cecil Roberts, issued a statement yesterday calling the lightning explanation "far-fetched" and "unsupported by physical evidence found and examined in the mine. We do not believe MSHA or anyone else has conclusively or satisfactorily demonstrated how a charge from a lightning strike over two miles away entered the sealed area of the mine without a conduit from the surface," Roberts added. "It’s also important to note that MSHA did not conclusively rule out a roof fall or other frictional activity as the cause of the ignition, which the UMWA believes is the most likely ignition source. Nevertheless, I would add that since both the state and federal agencies have concluded that lightning probably caused this tragedy, the UMWA believes that emergency regulations must be immediately put in place nationwide that will mandate protection for miners working underground, up to and including withdrawal of miners from underground areas of a mine in the event of an approaching storm that may generate lightning. Despite its conclusions about lightning being the cause of the ignition, MSHA’s report does not contradict the UMWA’s contention that whatever the source of the ignition, it was the conditions inside the mine at the time of the ignition that caused these 12 men to die. They are not dead today because lightning struck over two miles away from the sealed area, nor are they dead because of frictional activity in the sealed area. They are dead because substandard seals were approved by MSHA years ago and used in this mine; because a flawed ventilation plan was approved and implemented; because there was not a mine rescue team immediately available on the property; because there were inadequate functioning oxygen units available underground; and because there was no emergency refuge chamber for them to go to."

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