For example, Main told the families the longwall shearer "was totally out of compliance," according to several people who attended the family meeting. But Main repeatedly declined to characterize for reporters what the evidence uncovered so far said about how well Massey protected its workers.
"Once we conclude our full investigation, we'll be laying out the facts as we find them," Main said.
Still, the picture painted by MSHA officials Wednesday directly contradicted in many ways the theory that Massey Energy has tried to promote: That a huge, uncontrollable burst of methane -- with no coal dust involved -- caused a horrific explosion that overwhelmed any safety systems Massey could have had.
Massey officials have tentatively scheduled their own meeting with the miners' families for Friday at a Charleston hotel. Shortly before retiring, former Massey CEO Don Blankenship had promised the company would release more information to back up its theory.
"Our findings are different than MSHA's working theory, as we understand it," said Massey general counsel Shane Harvey. "We do not currently believe that there were issues with the bits or the sprays on the shearer that contributed to the explosion.
"We likewise do not believe that coal dust played a meaningful role in the explosion," Harvey said. "We currently believe that the mine was well rock dusted and that the mine exploded due to an infusion of high levels of a natural gas."
But MSHA released some evidence Wednesday that the agency said directly contradicted Massey's theory.
For instance, MSHA investigators said that they found no evidence of a major explosion on the "tailgate" end of the longwall face area. That's the part of the mine where Massey has pointed to a large floor crack it believes allow a huge influx of methane into the mine.
MSHA investigators believe the lack of such evidence supports their view that a smaller ignition of a smaller volume of methane occurred on the longwall tailgate, and then expanded through the mine, following a trail of coal dust.
Previously, the agency had publicly said that roughly 80 percent of the 1,800 samples taken showed inadequate "rock-dusting" to control explosive coal dust. Massey disputes the agency's testing procedures and the results.
MSHA investigators believe miners working in the longwall section on April 5 received some sort of warning -- either a spiked methane detector or, more likely, the actual ignition -- and shut down the shearer's power and water supply in an effort to stop any machinery that might make cause and explosion.
At least two of the workers appear to have tried to exit the area, making it 400 to 500 feet from the shearer to the middle of the longwall face in less than 90 seconds before the larger blast erupted, investigators said.
Stricklin said that MSHA is now investigating a report from a family member who says he was in the mine office at about 3 p.m., just minutes before the explosion, when the longwall section workers called to report such a problem. Massey has not produced any records of such a call, Stricklin said.
MSHA officials declined to answer specific questions about what sorts of ventilation changes Massey may have made at the mine, but said it is looking into whether such changes were made over the Easter weekend just before the explosion.
Reach Ken Ward Jr. at kw...@wvgazette.com or 304-348-1702.