"I don't know the answer to that, but I will get that to you as soon as I can," Wagner said.

Nearly 30 years ago, Congress gave MSHA the pattern of violations authority when it rewrote federal mine safety laws in 1977. Lawmakers said the need for the provision was "forcefully demonstrated" during the investigation of the Scotia Mine Disaster, in which two explosions killed 23 miners and three federal inspectors in Kentucky in 1976.

But Oppegard said that MSHA wrote rules for the pattern of violations process that wrongly allow for the issuing of those warning letters -- instead of simply citing companies when they meet the criteria and immediately stepping up enforcement to protection miners.

"They are not only adding this step, they are, I think, violating the statute," Oppegard said. "It eviscerates the statute."

Wagner said that the new leaders at MSHA under the Obama administration hope to rewrite the pattern-of-violations rules, which date back to 1990. But he conceded that MSHA did not include such a proposal on regulatory agendas issued in May or in December.

National media reports since Monday's horrific explosion have focused on Massey Energy's safety record and evidence of growing problems over the last year at the Upper Big Branch Mine.

On Thursday afternoon, MSHA made public documents covering the mine's most recent quarterly inspection, which ended March 31. During that time, the operation was cited at least nine times for illegal accumulations of coal dust.

Mine safety experts have said this week that the Upper Big Branch explosion was extraordinarily large, a potential indication that coal dust was involved and made a methane ignition far worse than it otherwise might have been.

Coal dust -- especially very fine "float dust" like that found at the Upper Big Branch Mine -- is know to be potentially deadly, but regulators and experts have for years known it can be controlled by using proper amounts of "rock dust" or powdered limestone that dilutes the coal dust to safe concentrations.

"The evidence of large quantifies of float coal dust is an alarming discovery in light of what occurred at this mine on Monday," said mine safety advocate Davitt McAteer, who ran MSHA during the Clinton administration.

MSHA records indicate inspectors found unsafe buildups of coal dust in the Upper Big Branch Mine at least as recently as March 15.

"The longwall belt has accumulations of fine coal dust, black in color over top of previously rock dusted areas from the belt tail roller to the belt head," said that day's inspection report from MSHA.

Another inspection report from late January for another portion of the mine described "float coal dust along the entire beltline" and at least two others outlined laboratory analysis that showed inadequate "rock dusting" in parts of the mine.

More recent MSHA inspection reports for visits to the mine since April 1 have not yet been made available by the agency.

But last quarter's inspection also included repeated citations for improper rock dusting and violations of the mine's ventilation plan.

In describing MSHA's policing of the Upper Big Branch Mine, Wagner said, "I think we feel that we used the tools that we have available."

But Wagner said he did not know if MSHA ever sought increased fines from the Upper Big Branch Mine for "flagrant violations," as allowed under the 2006 MINER Act.

And he said MSHA did not use its long-standing legal authority to seek a federal court order against any condition at the mine that created "a continuing hazard to the health or safety of miners."

"We did not use that section of the act, no," Wagner said. "I'm really trying to get an opinion from our lawyers to explain to me really what constraints they felt really existed to keep us from going <t40>...<t$> I don't think that's ever been used, and I think there's some reason that people haven't and I need to find that out."

<I>Staff writer Gary Harki contributed to this report.

Reach Ken Ward Jr. at kw...@wvgazette.com or 304-348-1702.

But despite what regulators concede were serious and growing problems, the U.S. Mine Safety and Health Administration never took stepped-up action to cite the Upper Big Branch Mine for a "pattern of violations," according to the documents.

Mine safety advocates this week were outraged at the results: A massive explosion Monday afternoon that left at least 25 miners dead in the worst U.S. coal mining disaster in a quarter century.

"We are not talking about parking tickets here," said Pat McGinley, a West Virginia University law professor and coal industry expert. "When a mine's ventilation system isn't working properly or there is an unacceptable accumulation of coal dust even for an hour, miners lives are put at risk."

Massey Energy CEO Don Blankenship has defended his company and the Upper Big Branch Mine, saying "Any suspicion that the mine was improperly operated or illegally operated or anything like that would be unfounded."

And on Thursday, MSHA officials began to defend their agency's performance. MSHA distributed talking points to congressional representatives. Top agency deputy Greg Wagner called the Gazette to respond after the paper posted an online story about the large number of withdrawal orders at the Upper Big Branch Mine, and MSHA's failure to step up enforcement with a "pattern of violations" order against the mine.

"We issued citations for every hazard we identified," Wagner said. "We held the operator accountable for correcting the problems that were cited.

"The problem we continue to have is that MSHA isn't responsible for the <t40>...<t$> we can't be in the mine all the time in every place in the mine," Wagner said. "The mine operator under the act has responsibility to maintain an environment free of recognized hazards."

Wagner was upset with a story that detailed a report prepared this week for Sen. Robert C. Byrd, D-W.Va., in which MSHA officials revealed that they had issued 54 withdrawal orders to the mine in 2009 and another seven such orders so far in 2010.

"That's way off the charts," said Tony Oppegard, a former MSHA staffer and longtime mine safety lawyer in Kentucky. "I've never heard of that amount of withdrawal orders in that short of a period of time."

Under federal law, MSHA generally does not have broad authority to simply close a troubled coal mine, unless it seeks a federal court injunction to stop anything its inspectors believe "constitutes a continuing hazard to the health and safety of miners."

But, on its own authority and without going to court, MSHA can issue what the law calls "withdrawal orders" that force all miners to be removed from areas until significant hazards are eliminated.

In the case of the Upper Big Branch Mine, most of the withdrawal orders -- 48 in 2009 and six during the first three months of this year -- were issued when inspectors found Massey subsidiary Performance Coal exhibited an "unwarrantable failure" to comply with federal health and safety standards.

One of the most series withdrawal orders was issued in December 2009 under a section of federal law that allows inspectors to respond to "imminent danger" that "could reasonably be expected to cause death or serious physical harm."

The withdrawal orders likely covered only portions of the sprawling Raleigh County mine, but the MSHA document does not specify that. The document does not detail the exact violations that led to the withdrawal orders, how long the closures lasted or how promptly Massey fixed the cited problems.

But the withdrawals did include four orders in 2009 and one so far this year where inspectors took action because of Massey's "failure to abate" previously issued problems.

The MSHA document indicates that the Upper Big Branch Mine qualified in November 2007 for being cited for a "pattern of violations," which would result in withdrawal orders for all subsequent serious violations until the mine has a full inspection with no serious citations.

MSHA issued a warning letter to the company in December 2007, advising Massey that it was in danger of being cited for a violation pattern.

Under federal law, operators must be cited and enforcement escalated if an operator "has a pattern of violations of mandatory health or safety standards <t40>...<t$> which are of such nature as could have significantly and substantially contributed to the cause and effect of coal" health and safety hazards.

But, according to the document prepared for Byrd, MSHA let the company avoid that because it "successfully reduced its rate" of serious violations.

MSHA also reviewed the Upper Big Branch Mine for a potential pattern of violations in October 2009 and concluded the company did not meet the criteria for such a designation.

In a phone interview, Wagner was not able to explain that decision.

"I don't know the answer to that, but I will get that to you as soon as I can," Wagner said.

Nearly 30 years ago, Congress gave MSHA the pattern of violations authority when it rewrote federal mine safety laws in 1977. Lawmakers said the need for the provision was "forcefully demonstrated" during the investigation of the Scotia Mine Disaster, in which two explosions killed 23 miners and three federal inspectors in Kentucky in 1976.

But Oppegard said that MSHA wrote rules for the pattern of violations process that wrongly allow for the issuing of those warning letters -- instead of simply citing companies when they meet the criteria and immediately stepping up enforcement to protection miners.

"They are not only adding this step, they are, I think, violating the statute," Oppegard said. "It eviscerates the statute."

Wagner said that the new leaders at MSHA under the Obama administration hope to rewrite the pattern-of-violations rules, which date back to 1990. But he conceded that MSHA did not include such a proposal on regulatory agendas issued in May or in December.

National media reports since Monday's horrific explosion have focused on Massey Energy's safety record and evidence of growing problems over the last year at the Upper Big Branch Mine.

On Thursday afternoon, MSHA made public documents covering the mine's most recent quarterly inspection, which ended March 31. During that time, the operation was cited at least nine times for illegal accumulations of coal dust.

Mine safety experts have said this week that the Upper Big Branch explosion was extraordinarily large, a potential indication that coal dust was involved and made a methane ignition far worse than it otherwise might have been.

Coal dust -- especially very fine "float dust" like that found at the Upper Big Branch Mine -- is know to be potentially deadly, but regulators and experts have for years known it can be controlled by using proper amounts of "rock dust" or powdered limestone that dilutes the coal dust to safe concentrations.

"The evidence of large quantifies of float coal dust is an alarming discovery in light of what occurred at this mine on Monday," said mine safety advocate Davitt McAteer, who ran MSHA during the Clinton administration.

MSHA records indicate inspectors found unsafe buildups of coal dust in the Upper Big Branch Mine at least as recently as March 15.

"The longwall belt has accumulations of fine coal dust, black in color over top of previously rock dusted areas from the belt tail roller to the belt head," said that day's inspection report from MSHA.

Another inspection report from late January for another portion of the mine described "float coal dust along the entire beltline" and at least two others outlined laboratory analysis that showed inadequate "rock dusting" in parts of the mine.

More recent MSHA inspection reports for visits to the mine since April 1 have not yet been made available by the agency.

But last quarter's inspection also included repeated citations for improper rock dusting and violations of the mine's ventilation plan.

In describing MSHA's policing of the Upper Big Branch Mine, Wagner said, "I think we feel that we used the tools that we have available."

But Wagner said he did not know if MSHA ever sought increased fines from the Upper Big Branch Mine for "flagrant violations," as allowed under the 2006 MINER Act.

And he said MSHA did not use its long-standing legal authority to seek a federal court order against any condition at the mine that created "a continuing hazard to the health or safety of miners."

"We did not use that section of the act, no," Wagner said. "I'm really trying to get an opinion from our lawyers to explain to me really what constraints they felt really existed to keep us from going <t40>...<t$> I don't think that's ever been used, and I think there's some reason that people haven't and I need to find that out."

<I>Staff writer Gary Harki contributed to this report.

Reach Ken Ward Jr. at kw...@wvgazette.com or 304-348-1702.