Don Blankenship, longtime Chief Executive Officer of coal giant Massey Energy, was indicted November 13 on charges that he consistently violated federal mine safety rules at the company’s Upper Big Branch Mine until an April 2010 explosion that killed 29 of 31 miners.

The Charleston, West Virginia Gazette reports that a federal grand jury charges Blankenship with “conspiring to cause willful violations of ventilation requirements and coal-dust control rules — meant to prevent deadly mine blasts — during a 15-month period prior to the worst coal-mining disaster in a generation.” The allegations come with a maximum prison sentence of 31 years.