10. South Fork Dam

Location: Johnstown, PA

Year of Fail: 1889

In 1889 the South Fork Dam unleashed a torrent of 20 million tons of water upon Johnstown, killing over 2,200 people. While the court deemed the dam break an “Act of God,” Johnstown residents pinned the blame on poor maintenance by the dam’s owners, who chose to patch leaks with straw and mud instead of performing the major fix necessary. Moreover, a previous owner removed and sold three cast-iron pipes responsible for regulating water release.