Federal prosecutors this week filed criminal charges against a former Massey Energy executive in connection with illegal practices at mines owned by the company that operated the Upper Big Branch (UBB) mine, site of the worst mining disaster in U.S. history.

Although the charges against David Craig Hughart are not specifically related to UBB, U.S. Attorney Booth Goodwin said they stem from an investigation into the April, 2010 explosion that killed 29 men.

Hughart, former president of a Massey subsidiary, allegedly – and illegally -- helped employees at Massey-owned mines receive advance warning about surprise federal inspections, giving them time to hide safety violations that could have led to citations, fines and costly shutdowns.

Goodwin said Hughart has indicated a willingness to plead guilty to two charges: felony conspiracy to defraud the government by impeding the Mine Safety and Health Administration (MSHA), and misdemeanor conspiracy to violate mandatory health and safety standards. With that plea, Hughart could face six years behind bars.

Hughart worked closely with former CEO Don Blankenship, the man thought by many victims’ families to be personally responsible for the tragedy. Blankenship retired about eight months after the disaster.

Former UBB superintendent Gary May pleaded guilty to a federal conspiracy charge for his actions at the mine and is scheduled to be sentenced in January.

Former Massey Energy security director Hughie Elbert Stover, who was sentenced to 36 months in jail for making a false statement and obstructing the government investigation into the UBB disaster, has remained free while appealing his conviction.

Witnesses in Stover’s case testified that he instructed mine guards to send radio alerts whenever inspectors entered the property.

UPP miner Thomas Harrah was sentenced to ten months in jail after pleading guilty to falsifying a foreman's license when he performed key mine safety examinations at the mine and to lying to investigators about his actions.

The United Mine Workers of America (UMWA) – which did not represent UBB workers – conducted its own investigation into the fatal explosion and found that Massey kept two sets of record books, one that documented actual conditions, and an “official” record that concealed the truth about unsafe conditions in the mine.

The UMWA report said that “management intimidation” and fear of reprisal, including job loss, kept employees from speaking out about hazards.

 “It is not believable that management personnel were unaware of the general poor conditions at the mine, and these conditions posed a substantial and immediate hazard to the miners and could possibly escalate into a catastrophic event,” said the report.