The recent attempts to rescue 33 trapped miners from the San Jose Mine in Copiapo, Chile have once again brought mining safety concerns to the forefront of our consciousness. Earlier this year, the United States experienced its worst mining disaster in 40 years when 29 miners were killed in Montcoal, West Virginia during the Upper Big Branch Mine explosion. Regardless of whether the site is located in a first world or developing country, mining has always been an extremely dangerous job in which the risk of death is ever-present. Since the beginning of the 20th century, thousands of Americans have been killed in mining accidents. Here are 10 major mining disasters that occurred in the states. The high death tolls are indicative of an era of carelessness and primitive technology.