The Upper Big Branch Mine Disaster occurred on April 5, 2010, in Montcoal, West Virginia. An explosion in the mine, operated by Massey Energy, resulted in the deaths of 29 miners. The incident was one of the deadliest coal mining disasters in the United States in recent history. Following the explosion, investigations revealed safety violations and inadequate emergency response measures at the mine. The disaster led to increased scrutiny of mining regulations and practices, prompting changes in safety standards to protect miners. The tragedy highlighted the ongoing risks associated with coal mining in the region.