A look at some of the worst floods in US history, from Hurricane Katrina to dam disasters

Yahoo

07-07-2025

The devastating flooding in Texas' Hill Country has shocked and scared the nation, with Americans from coast to coast waiting for news from ongoing rescue efforts.
Dozens of people have died – including young campers and counselors from an area summer camp – as floodwaters destroyed parts of central Texas. Unrelenting rain quickly changed the region's terrain: In Kerrville, Texas, a gauge measured the Guadalupe River's waters at less than a foot on July 3 to more than 34 feet in the early hours of July 4.
This was far from the first time Americans have mourned the victims of deadly floods. Here's what to know about some of the worst flooding events in American history, in order of most lives lost.
The deadliest flood in the nation's history was caused by a dam break upstream from Johnstown, Pennsylvania, according to the National Oceanic and Atmospheric Administration. More than 2,200 people in western Pennsylvania died as a result of the failure on May 31, 1889.
The South Fork Dam released 20,000 tons of water, according to the National Parks Service, and people can still visit the Johnstown Flood National Memorial today to pay tribute the the victims.
Hurricane Katrina devastated America's Gulf Coast in August 2005. The levee system in New Orleans failed as the Category 4 hurricane brought intense rain and winds, causing widespread destruction in the region.
Damage soared above $100 billion, according to the National Weather Service, and 1,833 people died. Images of Americans being rescued from rooftops are still ingrained in the country's memory.
The Great Flood of 1913 started in the Midwest on March 21, 1913, according to Case Western Reserve University. In a span of five days, storms dropped 11 inches of water on Ohio, which was as much rainfall as the state typically saw in three months.
Cities across the state – Cleveland, Columbus, Cincinnati and Dayton ‒ were all impacted. At least 467 people died, and the state estimated over $100 million in property damage.
The St. Francis Dam disaster is known as one of the worst failures of civil engineering in the 20th century.
The dam was built to create a reservoir northwest of Los Angeles, according to the United States Geological Survey. It collapsed just before midnight on March 12, 1928, according to the University of California – Los Angeles, killing approximately 450 people.
Nearly 12.4 billion gallons of water rushed along the San Francisquito Canyon, and water gauges measured 140 feet in parts of the region.
The floods along the Ohio River in 1937 were fueled by record-breaking rainfall, the Cincinnati Enquirer, part of the USA TODAY Network reported.
At least 350 people died in the flooding, according to the National Weather Service, and it left nearly 1 million people homeless as the nation grappled with the Great Depression. Rains brought parts of the river to an estimated 80 feet, and 15 to 20% of Cincinnati was covered by water.
This article originally appeared on USA TODAY: Deadliest floods in US history: Hurricane Katrina to dam disasters