CHARLESTON, W.Va. (AP) - A Massey Energy official said Thursday it is a "distinct possibility" that an unpreventable flood of methane gas caused the explosion that killed 29 men at the company's Upper Big Branch coal mine.
Readings collected by federal investigators from the Raleigh County mine's exhaust fan showed approximately twice as much methane as the roughly 1 million cubic feet a day the mine normally releases was present five-and-a-half hours after the blast, Massey said. The company suggested that a crack in the mine's floor could have been the source of a sudden surge of the volatile gas.
Participants in the civil investigation of the blast largely dismissed Massey's claims. The explosion also is the subject of a federal criminal investigation.
"The conditions after an explosion are entirely different. They're night and day to what was going on beforehand," said J. Davitt McAteer, appointed by Gov. Joe Manchin to conduct an independent investigation of the explosion. "To reach a conclusion based upon readings in the hours after an explosion is scientifically unsound and is not and doesn't make any logical sense."
That's exactly what Massey consultant Christopher Schemel tried during a conference call with reporters.
"What we can tell from the data is that on April 5th a large amount of methane was liberated into the UBB mine," said Schemel, an expert in fires and explosions. He said gas poured in fast enough to raise the methane level of a 2,000-square-foot house to explosive range in less than 40 seconds. Methane can explode when it's between 5 percent and 15 percent of the atmosphere.
"The data also suggests that this release was sustained at an elevated rate," Schemel said. "This methane is a distinct, possible source of this explosion."
Massey again said the methane may have come from a crack in the mine floor. The Eagle coal seam is prone to that phenomenon and Massey experienced inundations elsewhere at Upper Big Branch in 2003 and 2004.