Mine safety in coal mines, which in turn can initiate more extensive coal dust explosions. For this reason, rock dusts such as limestone dust are spread throughout coal mines to diminish the chances of coal dust explosions as well as to limit the extent of potential explosions, in a process known as rock dusting. Coal dust explosions can also begin independently of methane gas explosions. Frictional heat and sparks generated by mining equipment can ignite both methane gas and coal dust. For this reason, water is often used to cool rock-cutting sites. Miners utilize equipment strong enough to break through extremely hard
2008 Chelopechene explosions to close down as broken glass was reported at Terminal One and some debris landed on the runways. All flights were redirected to Plovdiv International Airport, about 160 kilometers east of Sofia. By Sunday, June 6 there were already rumours circulating that the explosions were intentionally caused. Defence Minister Nikolai Tsonev said that a fire (such as the one that caused the explosions) could not have accidentally occurred, and if it had indeed been an accident, that "whole blocks of flats would have been toppled". Instead, it was carefully engineered to spare casualties, Tsonev told reporters. He said that information