In Utah, hundreds of rescue workers are trying to find six coal miners who are trapped about 1,500 feet below ground.
The miners have not been heard from since Monday when a mine shaft collapsed. Officials said there was no indication whether the miners were alive or dead.
The non-unionized mine is owned by the Murray Energy Corporation.
The Associated Press reported that federal mine inspectors had issued hundreds of safety violation citations against the mine since January 2004 and had ordered the owner to pay nearly $152,000 in penalties.
More evidence that coal is dangerous to not only communities, eco-systems and the climate, but also to the workers themselves.