The Kumtor gold mine, operated by Centerra Gold, is located 4,000 meters above sea-level in the permafrost and glaciers of the Tien-Shan Mountains. The mine has endangered the welfare of nearby communities and the environment. In May of 1998, a truck crashed through a bridge near the village of Barskaun and dumped over 1.7 tons of sodium cyanide (and 935 kg of cyanide) into the Barskaun River. The company did not notify residents of Barskaun, who use the water for drinking and irrigation, until 5 hours after the accident. As a result, over 2,500 people were poisoned, 850 people were hospitalized and at least four of those patients died.