A former superintendent at Massey Energy’s Upper Big Branch (W.Va.) mine, where 29 miners were killed in an April 2010 explosion, pleaded guilty today to conspiracy to violate federal mine safety laws.

Gary May admitted to tipping off mine managers that inspectors from the federal Mine Safety and Health Administration (MSHA) were on their way, allowing them to clean up hazards like poor airflow and piles of loose coal that would have led to citations and fines. He also admitted to falsifying safety records and telling miners to rewire a device that monitored flammable methane gas levels, allowing mine equipment to run illegally, prosecutors said.

U.S. Attorney Booth Goodwin said:

People who run coal mines have a fundamental obligation to be honest with mine regulators. When mine operators resort to tricks and deceit to keep government officials in the dark, our mine safety system unravels and miners are put in harm's way. The least we can do for coal miners is protect the integrity of the laws designed to keep them safe.

Goodwin said May is cooperating with the ongoing investigation into the blast. He will be sentenced Aug. 9 and faces up to five years in prison. One former Massey supervisor has been sentenced to a jail term; another has been charged.

Yesterday in a House hearing, witnesses called for tougher mine safety laws and stronger penalties for violating safety and health laws.