The Monongah mining disaster of Monongah, West Virginia occurred on December 6, 1907, and has been described as "the worst mining disaster in American history." 362 miners were killed. The explosion occurred in Fairmont Coal Company’s No. 6 and No. 8 mines, and was one of the contributing events leading to the creation of the United States Bureau of Mines. The disaster On Friday, December 6, 1907, there were officially 420 men in the two mines, although the actual number was much higher as officially registered workers often took their children and other relatives into the mine to help. At 10:28 AM, an explosion occurred in one section of the mine, followed by a larger explosion in another area, instantly killing most of those inside. The blast caused considerable damage to both the mine and the surface. The ventilation systems, necessary to keep fresh air supplied to the mine, were destroyed, along with many railcars and other equipment. The entrance and ventilation fan of No. 8 mine were destroyed, "but did little damage to No. 6 slope." Inside the mine the timbers supporting the roof were blown down, which caused further problems as the roof collapsed. An official cause of the explosion was not determined, but investigators at the time believed that an electrical spark or one of the miners' open flame lamps ignited coal dust or methane gas. Rescue attempts The first volunteer rescuers entered the two mines twenty-five minutes after the initial explosion. The biggest threats to rescuers were the fumes, particularly “blackdamp”, a mix of carbon dioxide and nitrogen that contains no oxygen, and “whitedamp”, which is carbon monoxide. The lack of breathing apparatus at the time made venturing into these areas impossible. Rescuers could only stay in the mine for 15 minutes at a time. In a vain effort to protect themselves, some of the miners tried to cover their faces with jackets or other pieces of cloth. While this might have been able to filter out particulate matter, it would not have been able to protect the miners in an oxygen-free environment. The toxic fume problems were compounded by the infrastructural damage caused by the initial explosion: mines require large ventilation fans to prevent toxic gas buildup, and the explosion at Monongah had destroyed all of the ventilation equipment in No. 8 mine and disabled the fan in No. 6 mine. Rescuers were eventually able