The indictment of a former coal mining CEO over safety violations Thursday sent a “strong message,” said the United Mine Workers of America. Don Blankenship faces four criminal counts and up to 31 years in prison for alleged safety violations at mines operated by Massey Energy, which he headed from 2000 until his retirement in 2010.

“The carnage that was a recurring nightmare at Massey mines during Blankenship’s tenure at the head of that company was unmatched. No other company had even half as many fatalities during that time,” said  United Mine Workers of America International President Cecil E. Roberts.

The federal grand jury’s indictment charges that “Blankenship conspired to commit and cause routine, willful violations of mandatory federal mine safety and