The Upper Big Branch Mine disaster occurred on April 5, 2010, roughly 1,000 feet (300 m) underground in Raleigh County, West Virginia at Massey Energy's Upper Big Branch coal mine located in Montcoal. 29 miners were killed in the explosion, and 3 were injured. The coal dust explosion occurred at 3:27 pm. The incident was the worst in the United States since 1970, when 38 miners were killed at Finley Coal Company's No. 15 and 16 mines in Hyden, Kentucky. A state funded independent investigation later found Massey Energy directly responsible for the blast.