Former Massey Energy CEO Don Blankenship has pleaded not guilty to federal charges in a mine safety case.
Blankenship entered his plea on Tuesday at an arraignment hearing in U.S. District Court in Beckley. The hearing was based on a new, superseding indictment handed up earlier this month.
Blankenship also pleaded not guilty during his first arraignment in November.
He is charged with conspiring to violate safety standards, falsifying coal dust samples and defrauding federal financial regulators related to Upper Big Branch Mine. A blast at the southern West Virginia mine killed 29 men in 2010. It was the deadliest U.S. coal mine accident in four decades.
Blankenship could face up to three decades in prison, if convicted.