drowned during this event. ∉∀∈∘∀ Rapid City, South Dakota, flood – June 1972 A frontal zone was banked up against the Black Hills of South Dakota on the morning of June 9. Heavy rainfall, with amounts of nearly near Keystone, mainly between 6 pm and midnight. Rapid Creek overflowed at 10:15 pm. Canyon Lake Dam failed at 10:45 pm, adding to the flood's magnitude. The flood crest, reached around 12:15 am, ravaged Rapid City and surrounding canyons. The death toll was 238. The Rapid City Public Library hosts a more comprehensive digital archive of flood-related stories, photos and news accounts on their 1972 flood page. Hurricane Agnes flood – June 1972 Hurricane Agnes moved into the coast of the Florida panhandle as a weak hurricane. Weakening into a tropical depression over Georgia, a major trough in the Westerlies approached the cyclone, which subsequently strengthened Agnes over land back into a tropical storm in North Carolina, although it also developed a more western cyclone. The two moved in tandem, with Agnes moving offshore Norfolk, Virginia and becoming a strong tropical storm. Eventually, the western nontropical low wrapped Agnes inland, which was then absorbed over Connecticut. These cyclones led to of rain over North Carolina, with falling across the remainder of the Mid-Atlantic states. The flood unleashed by the system was the greatest natural disaster in damages for the United States up until that time. Michigan floods – April 1975 A major flood struck the Lower Peninsula of Michigan. In early April, a foot/30 cm of snow fell across the region. Intense rainfall on April 18 and 19 of fell over a short time frame into the residual snowpack, increasing the magnitude of the flood. The flood peaked between April 19 and 22, primarily in the Kalamazoo, Grand, Flint, and Shiawassee River basins. The recurrence interval for this kind of flood is 50–100 years. Lansing and Flint saw the most damage, which overall totaled US$50 million (1975 dollars). Big Thompson Canyon flood in Colorado (July 1976) Moist easterly flow went up the terrain of the Big Thompson River, forming thunderstorms beginning at 6 pm and lasting to 9 pm on July 31. of rain fell in one hour, with over falling during the event. A high fall of water swept down the canyon, taking everything in its path downstream. It was one of the deadliest natural freshwater floods in U.S. history, as