Charged Exec Cooperating in W.Va. Mine Blast Probe An executive who ran several coal companies for Massey Energy and worked closely with former CEO Don Blankenship faces criminal conspiracy charges and is cooperating with federal prosecutors, a sign that authorities may be aiming their sights even higher in the company as they probe a fatal West Virginia blast that was the nation's worst mine disaster in four decades. David Craig Hughart, president of a Massey subsidiary that controlled White Buck Coal Co., is named in a federal information document - which signals a defendant is cooperating - filed Wednesday in U.S. District Court in Beckley. Although Upper Big Branch is never directly mentioned in the document, U.S. Attorney Booth Goodwin told The Associated Press the charges come from the wide-ranging and continuing investigation of the April 2010 explosion that killed 29 men. Hughart (HYOO'-gurt) is the highest-ranking official yet to be charged, and his cooperation suggests that federal officials could be working their way up the Massey hierarchy. Blankenship was known for dealing directly with presidents of his subsidiaries, possibly even bypassing layers of management in between. Massey was bought after the disaster by Virginia-based Alpha Natural Resources, which has said it was sealing the mine permanently. The court document accuses Hughart of working with co-conspirators to ensure miners at White Buck and other, unidentified Massey-owned operations received advance warning about surprise federal inspections many times between 2000 and March 2010. Those illegal warnings gave workers time to conceal violations that could have led to citations, fines and costly shutdowns, the document says. Four investigations have concluded that Massey concealed problems at the mine through an elaborate scheme that included sanitized safety-inspection books and an advance-warning system. The United Mine Workers of America, which accused Massey of "industrial homicide," has demanded prosecution of at least 18 Massey managers, including Blankenship. Neither Blankenship nor one of his attorneys immediately responded to an email seeking comment Wednesday. Hughart could be the link prosecutors need to go up the Massey food chain. He's been president of at least 10 Massey subsidiaries throughout his career, positions that would have required the consent of a CEO whose micromanagement is well documented. At Big Branch, for example, Blankenship demanded production reports every 30 minutes. Investigators say that at other Massey mines, Hughart colluded with others to violate laws requiring adequate ventilation, the removal of explosive coal dust and the application of pulverized limestone to prevent explosions. Hughart has agreed to plead guilty to two charges: felony conspiracy to defraud the federal government by impeding the actions of MSHA, and misdemeanor conspiracy to violate mandatory health and safety standards. The felony charge carries a possible sentence of five years in prison. The misdemeanor carries up to one year. Goodwin wouldn't say who else might be charged or when. His investigators are "trying to push forward as quickly as we can," Goodwin said, but that developing the necessary evidence means obtaining the cooperation of people like Hughart. Hughart is the third person to face serious criminal charges in the mine-blast investigation.