On July 28, 1976, during the 7.6 magnitude Tangshan Earthquake, Tianjin was affected by the shock waves and suffered major loss of life. In the city, 24,345 people died and 21,497 were seriously injured. 60% of the city's buildings were destroyed and more than 30% of the enterprises and Peking Port Reservoir and Yuqiao Reservoir were seriously damaged. Nearly 700,000 people were left homeless. On October 10 of the same year, the Tianjin Underground Railway was opened to traffic. In 1981, Miyun Reservoir was built on the upper reaches of the Hai River and is used to supply water for Beijing, however the reservoir stopped the river from supplying water to Tianjin, resulting in difficulty in the use of water in Tianjin. In the same year, the State Council of the People's Republic of China decided to initiate a project to solve the problem of water use in Tianjin and attract talented individuals to the city's academic centers.