Top 10 Deadliest American Tornado Outbreaks of the Past 100 Years

At least 17 tornadoes tore through the Southeastern United States during mid-April 1920. The outbreak lasted 50 hours and affected several states, but Alabama, Mississippi, and Tennessee were hit the hardest. Many of the tornadoes were ranked as F4s on the 5-pillared Fujita scale – a system created to measure tornado intensity – and one of them was a near-F5 that killed 88 people all by itself. Bridges were wrecked, barns, schools and churches were crushed and roofs were torn from homes. In total, 243 people died, nearly 1400 were injured, whole communities were obliterated and damage was likely in the millions ofdollars.

Flint, Michigan and Worcester, Massachusetts were devastated by tornadoes from an outbreak that affected much of thenortheastern U.S. Starting as far west as Colorado, this band of tornadoes ripped through hundreds of miles of prairie landscape before arriving at the heavily populated East Coast. Because these areas fall outside what’s normally considered tornado alley, some believed atomic bomb testing caused this storm system – however, meteorologists quickly debunked this. One of the 46 confirmed tornadoes was an F5 that affected Flint and surrounding townships, flattening buildings with ease and killing 116 people, while an F4 hit Worcester and killed 90. These apocalyptic conditions lasted three days, caused over 245 deaths, and – if adjusted for inflation – $3 billion in damage.

The Sunday before Easter is referred to by Christians as Palm Sunday, and that’s the religious day that gave this deadly tornadooutbreak its name. Christians in the Midwest went to church that day with no storms in the forecast, but by the time it was over this storm system had destroyed tons of property, including churches themselves. In just one day, 47 tornadoes materialized in several Midwest states, with 17 of them landing in the F4 range. They claimed around 270 lives – 137 in Indiana alone, which isthe deadliest outbreak in the state’s history. Over 1,500 people were injured across Iowa, Indiana, Michigan, Ohio, Illinois, and Wisconsin, and the damage done would be worth $6 billion today. 

In terms of scale, the super outbreak of 1974 is the second largest in recorded history. In an 18-hour period, 148 tornadoes affected 13 states from Mississippi to New York in an unprecedented force of nature: 23 of the tornadoes were F4s and seven were F5s, equaling 30 violent tornadoes, which is a record for a single outbreak. 2,600 miles were hit, 900 square miles of land and buildings damaged, with costs of over $600 million in 1974 currency. All told, 319 people died and nearly 5,500 were injured. 

April 1974 hosted the second largest outbreak, but it was April 2011 that saw the largest ever recorded. An inconceivable 362 tornadoes spread throughout 21 states over three days – 363 if you count the one that touched down in Ontario. Regions from Texas to New York were hit with torrential winds, hail, and rain, along with 11 F4 and four F5-rated tornadoes – although Alabama and Mississippi were hardest hit. The cost of this atmospheric wrecking ball was $11 billion: an unparalleled amount for a tornado outbreak. The fallout did not end with uprooted trees, however, as 324 people were killed – 317 of those in one day – and 252 people in Alabama alone.

It seems that Alabama is a tornado magnet. While this 13-hour outbreak affected nearly all of the southern states, Alabama wasthe worst hit – as usual. 268 of the roughly 330 fatalities occurred in Alabama due to eight F4 scale tornadoes in the state. There were ten violent tornadoes in total, as part of a larger group of 36, and they ravaged cities and towns of the entire southeast portion of the United States, spreading from Mississippi to Illinois to South Carolina. Over 2,000 injuries were reported after the outbreak, along with $5 million in damage – and that’s in 1932 currency. 

Yes, you heard that right: two of the most devastating tornado outbreaks occurred on Palm Sunday, with the 1920 event beingthe deadliest. There were 37 tornadoes in total, and they wreaked havoc on an area larger than Germany, tearing down churches and surprising farmers. It’s estimated that around 380 people were killed in several states, with Indiana, Georgia, and Ohio receiving the brunt of the wrath. However, some historians theorize that the loss-of-life was actually far greater, as records for the deaths of non-white citizens were not kept at that time. Along with the incredible loss of life, over 1,200 people were injured by the funnel clouds and their projectile debris. 

As you can deduce by the title, this wasn’t a single-day event: the 1917 tornado outbreak lasted an unbelievable eight days and massacred many states in the Midwest and Southeastern United States. From Nebraska to Texas to Alabama, this family oftornadoes travelled, toppling significant towns and farming communities. Of the 73 tornadoes, 15 were considered violent, including an F5 that struck southern Kansas and demolished over a hundred buildings. 383 people were reported dead after thechaos ended, and the resulting damage was in the hundreds of millions of dollars if adjusted for inflation.

The outbreak only consisted of a seemingly paltry 12 tornadoes, but this disaster claimed more lives than nearly all the other entries on our list. There were fatalities in six different states, but Mississippi and Georgia had over 90 percent of the death toll. A single tornado attacked Tupelo, Mississippi on April 5 and killed at least 216 people, while another tornado hit Gainesville, Georgia on April 6 and left over 203 people dead. In only 16 hours, the tornadoes killed 454 people, injured 2,500 and becamethe continuous tornado outbreak in the history of the U.S. to yield more than one tornado with fatalities in the triple digits.

Before we unveil our top pick, here are a few dishonorable mentions:
- May 21-26, 2011 Outbreak Sequence [including Joplin Tornado]
May 21-26, 2011

Casualties: 178 fatalities, 1,589 injuries

- March 1952 Southern United States Outbreak
March 21-22, 1952

Casualties: 209 fatalities, ≥1,212 injuries

- 1947 Glazier-Higgins-Woodward tornadoes
April 9, 1947

Casualties: ≥ 181 fatalities, ≥ 980 injuries

- 1944 Appalachians Outbreak
June 22-23, 1944

Casualties: 163 fatalities, ≥1044 injuries

- March 1942 Outbreak 
March 16-17, 1942

Casualties: 153 fatalities, ≥ 1,284 injuries

The Great Tri-State Tornado outbreak occurred on Wednesday, March 8, 1925 and greatly affected Missouri, Illinois, and Indiana. Despite lasting only seven hours and consisting of just 12 tornadoes, this outbreak is the deadliest in the history of theUnited States. Over 747 people were killed, with 695 of those from a single tornado that travelled 235 miles and destroyed some 13 counties and 19 communities across the three affected states. Undisputedly, it has since earned an F5 rating from most experts, as it was the deadliest individual tornado in American history. All in all, the outbreak caused over $2 billion in damage if adjusted for inflation, and left around 2,300 people injured.

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