CHARLESTON, W.Va. -- Federal prosecutors are continuing their investigation of the Upper Big Branch Mine Disaster and of broader safety issues at the former Massey Energy, U.S. Attorney Booth Goodwin says.Goodwin said Friday that the probe remains ongoing, despite the end of his office's two years of oversight of safety improvements mandated by a related deal with Alpha Natural Resources, which bought Massey after the disaster."My office's resolution with Alpha required the company to make safety-related payments and investments totaling at least $210 million by December 2013 -- by far the largest monetary sanction in a mine safety investigation," Goodwin said. "Alpha met that deadline.""My primary focus continues to be on the investigation of misconduct by individual officials of the former Massey Energy," Goodwin said. "That investigation has resulted in three criminal convictions to date, including the conviction of a former Massey division president, and it remains ongoing."Twenty-nine miners died in the April 5, 2010, explosion at Massey's Upper Big Branch Mine near Montcoal in Raleigh County.Four government and independent investigations blamed the Upper Big Branch deaths on a pattern by Massey Energy of violating federal standards concerning mine ventilation and the control of highly explosive coal dust, both of which set the stage for a small methane ignition to turn into a huge coal-dust-fueled explosion.In December 2011, Goodwin reached a deal not to prosecute Alpha Natural Resources for any Upper Big Branch criminal liabilities that it inherited when it purchased Massey Energy six months earlier. That deal required the company to spend $80 million during the next two years on mine safety improvements and create a $48 million mine safety research trust fund. Alpha also agreed to pay $46.5 million in restitution to families of the disaster victims and $35 million to resolve pending Massey safety fines, including $10.8 million levied for violations related to the Upper Big Branch explosion.Goodwin's deal allowed federal officials to pursue potential criminal cases against any individuals - including Massey executives - for violations related to the mine disaster.The three criminal convictions cited by Goodwin were:| Former Massey official and division president David Hughart was sentenced 42 months in prison after he pleaded guilty to one felony count of conspiracy to defraud the government by thwarting U.S. Mine Safety and Health Administration inspections and one misdemeanor count of conspiracy to violate MSHA standards.| Former Upper Big Branch superintendent Gary may was sentenced to 21 months in prison after admitting to one felony count of conspiracy to thwart federal government mine safety efforts.| Former Upper Big Branch security director Hughie Elbert Stover was sentenced to 36 months in jail after he was convicted in a jury trial of two felonies, making a false statement and obstructing the government's mine disaster probe.Also, former UBB miner Thomas Harrah was sentenced to 10 months in prison after he admitted to faking a foreman's license when he performed key mine safety examinations at the mine between January 2008 and August 2009, and then lied to investigators about his actions.Last week, Alpha Natural Resources issued a press release to announce that Goodwin's office had "closed" work on its "non-prosecution agreement," or NPA, with the company."We are pleased that the U.S. Attorney determined that Alpha has met or exceeded its obligations under the NPA," said Alpha Executive Vice President and General Counsel Vaughn Groves. "Throughout this process, we remained committed to responsibly addressing the UBB tragedy and resolving Massey's liabilities, while implementing safety measures, training and research that will make our industry safer for miners not just today, but well into the future."Alpha listed some steps it said the company had taken under the deal with Goodwin:| Building a new training facility at the company's regional headquarters in Julian.| Funding a $48 million foundation dedicated to financing mine safety and health research.| Working to develop and then install at its underground mining operations new atmospheric monitoring sensors that improves the ability to detect ventilation problems.| Reducing Alpha's total reportable incident rate by 31 percent.| Providing restitution to families of the miners who died at Upper Big Branch.Under the settlement, Alpha was required for two years to provide progress reports to Goodwin's office every six months describing its compliance with the terms of the deal.So far, Goodwin's office and the U.S. Department of Justice have refused to make public those detailed compliance reports submitted by Alpha.Among other things, the progress report was to contain a "current list of expenditures" made in connection with the settlement. Alpha was also to conduct special "safety compliance visits" at all of its mines, and submit a report of the findings - and steps taken to remedy any problems -- to Goodwin's office.Alpha was also to implement a plan to ensure that each of its underground mines "has the personnel and resources necessary to meet all legal requirements related to incombustible material and to prevent accumulations of coal dust and loose coal."None of Alpha's detailed reports on those issues have been made public.In a prepared statement Friday, Goodwin said, "Information from Alpha regarding safety-related changes at former Massey mines inherently discloses evidence about the operation of those mines under Massey, which bears directly on our ongoing investigation. Consequently, we are not releasing that information at this time."Reach Ken Ward Jr. at email@example.com or 304-348-1702.