During a 5-month period in 2006, three underground coal mining incidents in the United States resulted in the deaths of 19 miners. All three incidents received nationwide attention, particularly the Sago Mine disaster, which occurred on January 2 and resulted in the deaths of 12 miners. The other two incidents, which occurred at the Alma No. 1 Mine on January 19 and the Darby No. 1 Mine on May 20, resulted in the deaths of two miners and five miners, respectively. The occurrence of three fatal incidents in 5 months was a departure from recent trends in underground coal mining safety. Before 2006, the number of mining disasters had decreased from a high of 20 in 1909 to an average of one every 4 years during 1985-2005. Deaths resulting from the three incidents were the stimulus for the Mine Improvement and New Emergency Response Act of 2006 (MINER Act) , which amended the Mine Safety and Health Act of 1977 to improve safety, health, preparedness, and emergency response in U.S. mining. This report briefly describes the three 2006 mining incidents, reviews mining disasters in the United States during 1900-2006, and traces the effect of the disasters and the 2006 incidents on mining health and safety regulations.