The U.S. Mine Safety and Health Administration (MSHA) has launched an investigation into a Westmoreland Coal Company miner’s death.

On Saturday, May 6, Michael Ramsey, a 62-year-old worker from Colstrip, Mont., was operating a dump truck at Westmoreland’s Rosebud Mine when the 100-ton haul vehicle fell 100 feet into a pit, according to news reports.