22. Taum Sauk Reservoir
Year of Fail: 2005
With an upper reservoir 800 feet above the hydroelectric plant it served, Taum Sauk had a larger head than The Hoover Dam. When a section of the reservoir gave way in 2005, one billion gallons of water rushed down a small creek toward two state parks. The superintendant of the parks, along with his wife and three kids, were swept away when a wall of water demolished their house. Reports found that a computer malfunction caused the reservoir to continue filling despite the water being at maximum level. The added weight caused the walls, which had been weakened by prolonged leaks, to crumble like piecrust.