A great, devastating flood of history was The Big Thompson Canyon Flood. This flood killed over a hundred people in 1976. This occurred in Denver, Colorado, on July 31, 1976. People were camping out, unaware that such a disaster would happen. A weak flow was occurring at the east side of the Rockies. The air rose up the hills, enhanced by heating. This made cumulus clouds form. They soon turned into cunucolimbus clouds, followed by a thunderstorm, then heavy rainfall. It stayed still over the mountain. The slope that led to the Big Thompson Canyon was made completely out of rock. This made it easy for rain to fall right into the Big Thompson River. Of course, this caused an overflow in the river. Eight inches of rain fell in an hour. The water…show more content… This happened in the Mississippi Valley in 1993. People think that this flood was the cause of the National Weather Service forming. This flood is probably the most devastating and critical floods in recent history. In 1992, the soil was very moist. Melting snow and rain in the summer contributed, leaving spring precipitation to run to rivers and streams. By June 1st of 1993, rivers were running at high levels. Disturbances in the air brought along horrible thunderstorms. These storms brought tons of rainfall, drenching the already soaked Mississippi River. Some areas were getting about 30 inches of rainfall, almost twice as much than normal. Mississippi wasn't the only state affected by the flood, however. Minnesota, Iowa, Illinois, and Missouri were hit the heaviest. St. Louis had their river at 49.6 feet, breaking the record of highest flood. Many levees failed to work, although some cities had defensive mechanisms that worked. Over 70,000 people were injured, 50,000 homes destroyed, and 52 people dead. The damages were extremely expensive. It was even higher than the population of the world. The cost was around $15-20 billion dollars! A devastating disaster