Two workers were killed Friday when their truck was crushed under falling rock at a surface coal mine in western Kentucky.
Rescuers worked most of the morning to reach the men under the rubble at Armstrong Coal's Equality mine in Ohio County.
Ohio County coroner Larry Bevil said crews reached the men around noon, but they were likely killed immediately by the "huge pile" of rock.
A statement from the Kentucky Office of Mine Safety and Licensing identified the workers as Darrel Winstead, 47, and Samuel Lindsey, 23.
The two men were on a blasting crew from MEMSCO, which is based in Dawson Springs and is a subsidiary of Midland Powder Co. of Evansville, Ind.
They were driving near a high wall when their truck was inundated by rock and earth at around 6:45 a.m. CDT.
"Mine safety is of paramount importance, and investigative teams will begin work immediately to determine the cause of this accident and whether there are any steps that can be taken to ensure such an accident does not occur again," Kentucky Gov. Steve Beshear said in a statement Friday.
U.S. Sen. Rand Paul, R-Ky., in a statement offered his condolences and said he appreciates "the dedication of Kentucky's coal community."
A spokesman at Armstrong Coal did not return a call seeking comment on Friday. Armstrong began operating the mine in December 2008, and it has recorded no previous accidents.
State officials, as well as investigators with the U.S. Mine Safety and Health Administration, are investigating.
There have now been six mine-related deaths in Kentucky in 2011.