The city of Johnstown, in southwest Pennsylvania (east of Pittsburgh), has been the site of numerous floods, but the most disastrous one occurred on May 31, 1889, when the South Fork Dam on the Conemaugh River gave way, releasing a torrent of water. Since the dam was located some 14 miles into the Allegheny Mountains, the waters rushed into Johnstown at a rate of 50 miles per hour. The water hit with a force strong enough to have tossed a 48-ton locomotive one mile. It killed more than 2,000 people; some sources place the estimate as high as 5,000 lives lost. At the time of the flood, the city’s population was about 30,000, meaning between 6 and 16 percent of the population died as a result of the disaster. In 1977 Johnstown was again the site of a disastrous flood, though advance warning systems helped minimize the loss of life to 77.