"Our experts feel confident that coal dust did not play an important role," Harvey said. "Our experts continue to study the UBB explosion and our goal is to find answers and technologies that ultimately make mining safer."
But McAteer's report contains an entire chapter, called "The Footprint of a Disaster," that details the physical evidence supporting the conclusion that coal dust fueled the explosion's rush into far corners of the mine.
Joe Main, assistant labor secretary in charge of MSHA, welcomed parts of McAteer's report that support his agency's version of what happened at Upper Big Branch. And, Main said, his agency has learned lessons from the disaster.
"Could we have done more? The answer is yes," Main said. "And have we done more? The answer is yes. We're using tools that weren't in use on April 4."
McAteer's report revealed that Gerald Pauley, the state's main inspector assigned to Upper Big Branch, did not always complete his inspections of the site and had not examined the crucial longwall section since Dec. 15, 2009.
Senate President Earl Ray Tomblin, acting as governor, said the state Office of Miners Health, Safety and Training has already shifted resources to give inspectors more time for larger mines like Upper Big Branch.
"Our inspectors are now working more frequently on weekends, allowing for inspections, as the report suggests, at any hour and on any day," Tomblin said in a statement.
Manchin said that McAteer's report makes clear that "this tragedy could have been prevented and these types of mistakes should never be repeated."
The report recounts Massey's long-troubled history of mine safety and environmental disasters, and concludes the company has "an inadequate commitment to safety ... coupled with a window dressing safety program."
"The story of Upper Big Branch is a cautionary tale of hubris," the report says. "A company that was a towering presence in the Appalachian coalfields operated its mine in a profoundly reckless manner, and 29 miners paid with their lives for the corporate risk-taking."
The report notes that Massey's vice president for operations, Chris Adkins, is scheduled to become co-director of Alpha Natural Resources' main safety program after Alpha completes its acquisition of Massey next month.
McAteer said he's concerned that Alpha executives "have not grasped the magnitude of the problem" with Massey's safety culture and practices. "Those questions need to be answered by the purchasing company," he said.
The report proposes a long list of reforms, including more resources for regulatory agencies, tougher enforcement of existing safety standards, and beefing up of those rules with new legislation.
McAteer urges the coal industry to put as many resources into improving mine safety technology as it has into mine production advances and says lawmakers should make corporate officials more accountable for safety violations.
And, the report calls for an overhaul of the way serious mining accidents are investigated in the first place, allowing for a more public and transparent process.
McAteer's team also blames the disaster in part on the coal industry's longstanding influence on West Virginia politics.
"The reality that powerful industries and their leaders cast long shadows over the state's government is not unique to West Virginia, nor is it unique to the coal industry," the report says. "It is a problem facing regulators of any large industry.
"But, with a powerful national lobby, the coal industry poses unique challenges for small state agencies that try to regulate it with inadequate resources," the report says. "For those dedicated safety officials and for the workers whose lives hang in the balance, the politics of coal must be acknowledged in any discussion of workplace safety and a commitment must be made to ensure that the public interest -- miners' safety -- is the foremost consideration."
McAteer's team is the first to complete its investigation into the worst U.S. coal-mining disaster in nearly 40 years. Separate federal and state probes aren't expected to wrap up until late this year at the earliest. Although Upper Big Branch was a non-union mine, the United Mine Workers also plans a report on the disaster.
A federal criminal probe is also ongoing. So far, only two low-level Massey employees have been charged.
Reach Ken Ward Jr. at kw...@wvgazette.com or 304-348-1702.