Last year I attended the 96th Annual Lithuanian Festival in Frackville, Pennsylvania. One of the nearby towns had a coal mining museum where you could actually go inside a former working coal mine.
I took the tour and was surprised to see just how bad working conditions really were. I found two relatives in the list of coal mining accidents that John provided the URL for.
I found a 1930s vintage news article about another ancestor (Charles Klokis nee Kliokys)who was working in a coal mine when there was a cave-in at the opening of the mine. He and the other miners were totally unaware of it. As they were returning to the mine opening to leave at the end of the day, they encountered the "rescue party" that had cleared the opening of the mine and were proceeding deeper into the mine when they found Charles and the others.