All before 1973
http://www.theworstdaily.com/5-worst-floods-in-us-history/
5. Rapid City, South Dakota (1972)
Flash food with a death toll was 237. That’s extreme, considering a flash food is simply rain over a short period — just a matter of hours.
4. Santa Paula, California (1928)
The St. Francis Dam collapsed, killing 450.
3. Ohio River (1913)
Rain over days, weeks, and months caused the Ohio river to exceed it’s banks and convert nearby cities and towns into part of the lake. New meaning for lakehouse, I guess? (Har, Har).
2. Mississippi Valley (1937)
Heavy rains took the lives of 1,100 people, destroying 75,000 homes and leaving 600,000 homeless.
1. Johnstown, Pennsylvania (1889)
Several days of heavy downpours caused the upriver South Fork dam to collapse, sending millions of gallons of water downstream toward the town of Johnstown. This was the first major disaster relief effort handled by the American Red Cross and it’s founder Clara Barton.
