Two U.S. coal miners died in separate accidents in two different states last week, according to the Mine Safety and Health Administration (MSHA).

A miner killed last Tuesday at Drummond Mining Company's Shoal Creek Mine in Alabama was identified by the MSHA as Julius Walker III, 28.

Walker died after being pinned against the mine wall by a large piece of equipment as it was being moved. Efforts to resuscitate him using CPR were unsuccessful.

A shuttle car engineer was killed in an accident at the same mine in March.

In West Virginia, 61-year-old Edward Mock was killed by being struck by a rock from the roof or wall of the mine.

Both mines were closed temporarily while investigations into the incidents were begun.

United Mine Workers of America (UMWA) International President Cecil E. Roberts said the union is participating in the investigations, “so that we can find out exactly what happened and do everything possible to keep these kind of incidents from ever happening again.

“While those investigations are underway, I urge every miner to be more vigilant than ever in identifying unsafe working conditions and staying away from them. If it’s not safe, don’t do it.”