CHARLESTON, W.Va. -- Federal prosecutors and mine safety officials are continuing to closely examine events at an Alpha Natural Resources mine in Wyoming County where a burned conveyor belt prompted the largest inspection sweep ever of a single company's mines.

Three-dozen Alpha operations were cited with a total of 226 violations in the one-day inspection blitz that the U.S. Mine Safety and Health Administration conducted May 23.

Six mines targeted by MSHA received no citations, but one of those was no longer mining and others had been shut down by a federal "imminent danger" order just one day before the agency's inspection sweep.

The incidents came as Alpha reached Friday's one-year anniversary of its $7 billion buyout of Massey Energy, and just days before the June 6 due date for it to report to U.S. Attorney Booth Goodwin on its progress improving safety at the former Massey mines.

Goodwin's office and MSHA were looking most closely at the incident two weeks ago at Alpha's Road Fork No. 51 Mine, where inspectors alleged the company wrongly did not evacuate the mine after miners encountered thick smoke from a burned conveyor belt.

Alpha had downplayed that incident in a report filed with the U.S. Securities and Exchange Commission, saying there was no fire and later telling the media company officials responded appropriately.

But Bruce Stanley, a lawyer for the widows of two miners -- Don Bragg and Ellery "Elvis" Hatfield -- who died in a conveyor belt fire at Massey's Aracoma Alma No. 1 Mine in January 2006, disagreed with the company's assessment.

"I suppose if they don't die on your watch, the lesson isn't learned," Stanley said Friday.

Three-dozen Alpha operations were cited with a total of 226 violations in the one-day inspection blitz that the U.S. Mine Safety and Health Administration conducted May 23.

Six mines targeted by MSHA received no citations, but one of those was no longer mining and others had been shut down by a federal "imminent danger" order just one day before the agency's inspection sweep.

The incidents came as Alpha reached Friday's one-year anniversary of its $7 billion buyout of Massey Energy, and just days before the June 6 due date for it to report to U.S. Attorney Booth Goodwin on its progress improving safety at the former Massey mines.

Goodwin's office and MSHA were looking most closely at the incident two weeks ago at Alpha's Road Fork No. 51 Mine, where inspectors alleged the company wrongly did not evacuate the mine after miners encountered thick smoke from a burned conveyor belt.

Alpha had downplayed that incident in a report filed with the U.S. Securities and Exchange Commission, saying there was no fire and later telling the media company officials responded appropriately.

But Bruce Stanley, a lawyer for the widows of two miners -- Don Bragg and Ellery "Elvis" Hatfield -- who died in a conveyor belt fire at Massey's Aracoma Alma No. 1 Mine in January 2006, disagreed with the company's assessment.

"I suppose if they don't die on your watch, the lesson isn't learned," Stanley said Friday.

"I suspect that belt fires are a relatively common occurrence underground, and rather than being trained to evacuate, miners are conditioned to keep working while somebody is given the task of trying to put it out," Stanley said. "At Aracoma, we were able to confirm that two belt fires occurred in the days before the fatal fire, including one in the very same location that revealed the litany of problems that condemned Don and Elvis to death.

"No evacuation occurred in either occasion," Stanley said. "Instead, they just kept running coal. It sounds like that same cycle is taking place at Road Fork. Hopefully, the federal intervention will break that cycle, but I'm not holding my breath."

MSHA investigators found inoperable smoke detectors and fire suppression systems, inadequate conveyor belt maintenance, and multiple accumulations of explosive coal dust as deep as 18 inches, according to the MSHA inspection records. Federal inspectors alleged that mine managers who performed company safety checks often did not report obvious safety hazards in required record books and did not correct dangerous conditions that they did list in those books.

Goodwin said his office takes "reports such as the one from Road Fork 51 very seriously" and intends "to closely review" MSHA's inspection findings for potential criminal violations.

Already, Goodwin's office is in the midst of trying to move its criminal investigation of the Upper Big Branch Mine Disaster up the ladder of former Massey mine management and corporate executives. In December, prosecutors agreed not to bring corporate criminal charges against any former Massey subsidiaries or against Alpha, but did not give up the ability to charge individuals found responsible for the April 2010 explosion that killed 29 miners.

As part of the deal with Goodwin, Alpha was to implement a plan to ensure that each of its underground mines "has the personnel and resources necessary to meet all legal requirements relating to incombustible material and to prevent accumulations of coal dust and loose coal."

On top of the three major coal-dust violations found at the Road Fork Mine, MSHA inspectors also issued 18 other dust-related violations at other Alpha mines targeted by the inspection sweep, said agency spokeswoman Amy Louviere.