From the New Richmond Heritage Center

On April 30, 2011, Southerners found their emergency safety net shredded as they tried to emerge from the nation's deadliest tornado disaster since the Great Depression. More than 340 people died from the storms across seven states, including 238 in Alabama, making it the deadliest U.S. tornado outbreak since March 1932, when another Alabama storm killed 332 people. Tornadoes that swept across the South and Midwest in April 1974 left 315 people dead.

11 New Richmond, Wisc.; June 12, 1899; 117 deaths
From the New Richmond Heritage Center

The 1899 New Richmond Tornado was an unprecedented disaster in the United States Upper Midwest. It nearly destroyed the village of New Richmond, Wisc., on June 12, 1899, killing 117 and injuring 125 people. More than $300 million in damage was reported (1899 dollars).

Photo: An image of the completely destroyed New Richmond Methodist Church after the 1899 tornado which killed 117 people.

10 Amite, La., and Purvis, Miss.; April 23-25, 1908; 143 deaths
Courtesy U.S. National Weather Service, NOAA

The 1908 Dixie tornado outbreak was among the worst tornado disasters in United States history. The outbreak produced tornadoes in 13 states from April 23-25, 1908, with the second worst loss of life in the Southeastern United States at the time. More than 100 years later, in April 2011, the death toll of a tornado outbreak in the same region has reached at least 340.

Photo: Tornado damage in Amite, La., April 24, 1908.

9 Joplin, Mo.; May 22, 2011; 151 deaths (as of June 10, 2011)
AP Photo/Jeff Roberson

The massive tornado that ripped through the heart of the blue-collar southwest Missouri city of 50,000 people was the deadliest single tornado since 1950. The National Weather Service rated the storm an EF5, the highest rating based on inflicted damage. An estimated 8,000 buildings were destroyed.

The tornado slammed straight into St. John's Regional Medical Center, one of the hardest-hit areas in Joplin, Mo. The hospital confirmed that five of the dead were patients — all of them in critical condition before the tornado hit. A hospital visitor also was killed.

Photo: Meghan Miller stands in the middle of a destroyed neighborhood as she checks on her sister-in-law's home Monday, May 23, 2011, in Joplin , Mo.

8 Woodward, Okla.; April 9, 1947; 181 deaths
Woodward County

The 1947 Glazier-Higgins-Woodward tornadoes were a system of related tornadoes that swept through Texas, Oklahoma, and Kansas on April 9, 1947. The event was similar to the Tri-State Tornado two decades before, in that it appeared to observers to be a single, very long-lived tornado. Later analysis suggests that it was a multiple-tornado outbreak. These tornadoes, although deadly, did not match the astounding death toll of the earlier event, nor did they match the record speed of that tornado, although at over 40 miles per hour, they qualified as a fast tracking storm.

Photo: The Woodward County Courthouse stood as a lone building after the storm. Most windows were blown out, and records in the courthouse still show water spots to this day.

7 St. Louis, Mo., and East St. Louis, Ill.; May 27, 1896; 255 deaths

The 1896 St. Louis-East St. Louis tornado is an historic tornado event that occurred on Wednesday, May 27, 1896, as part of a major tornado outbreak across the Central and Eastern United States. One of the deadliest and most destructive tornadoes in U.S. history, this very large, long-track, and violent tornado was the most notable of an outbreak which produced other large, long-track, violent, killer tornadoes. It caused over $10 million in damage (1896 dollars).

Photo: Tornado damage at Jefferson and Allen Ave in the City of St. Louis, 27 May 1896.

6 The Super Outbreak; April 3-4, 1974; 315 deaths

The Super Outbreak is the second largest tornado outbreak on record for a single 24-hour period. From April 3 to April 4, 1974, there were 148 tornadoes confirmed in 13 states, including Illinois, Indiana, Michigan, Ohio, Kentucky, Tennessee, Alabama, Mississippi, Georgia, North Carolina, Virginia, West Virginia, and New York; and the Canadian province of Ontario. It extensively damaged approximately 900 square miles along a total combined path length of 2,600 miles. The Super Outbreak of tornadoes remains the most outstanding severe convective weather episode of record in the continental United States. The outbreak far surpassed previous events in severity, longevity and extent. With a death toll of 315, the outbreak ranks among the deadliest of the recent years, now surpassed by the April 25–28, 2011, tornado outbreak in the Southeast.

Image: Tracks of tornadoes generated during the 1974 Super Outbreak.

5 Natchez, Miss.; May 7, 1840; 317 deaths
Thomas and Joan Gandy Collection, LSU Libraries Special Collections

The Great Natchez Tornado hit Natchez, Miss., on May 7, 1840. It remains among the earliest single-deadliest tornadoes in U.S. history. It is also reportedly the only recorded massive tornado in the U.S. that killed more people than it injured: only 109 were injured. The Fujita scale rating of this tornado is almost certainly an F5 but since there was no Fujita scale at the time, this tornado remains uncategorized.

Photo: Trolley in Natchez, Miss., circa late 1800s.

4 1932 Deep South; March 21-22, 1932; 332 deaths

The 1932 Deep South tornado outbreak is a deadly tornado outbreak that struck the southern United States on March 21-22, 1932. The outbreak produced tornadoes from Texas to South Carolina, and as far north as Illinois. Alabama was hardest-hit; the outbreak is considered to be the deadliest ever in the state, and among the worst ever in the U.S.

3 Southeastern United States; April 27-28, 2011; 340 deaths
AP Photo/Charles Dharapak

A violent tornado outbreak from April 27-28, 2011, affected the Southern and Eastern United States, leaving catastrophic destruction in its wake, especially across the state of Alabama, ravaging Tuscaloosa and Birmingham. The outbreak produced destructive tornadoes as large as nearly a mile wide in Alabama, Arkansas, Georgia, Mississippi, North Carolina, Tennessee, and Virginia, and affected several other areas throughout the Southern and Eastern United States. Winds were estimated at more than 150 miles per hour. Widespread and destructive tornadoes occurred on each day of the outbreak.

Photo: Photo taken from Air Force One shows the path of tornado damage as the plane approaches the airport in Tuscaloosa, Ala., Friday, April 29, 2011, prior to President Barack Obama's ground tour of the area.

2 Tupelo-Gainesville Outbreak; April 5-6, 1936; nearly 420 deaths
AP Photo/Hall County Library System via The Times

The 1936 Tupelo-Gainesville tornado outbreak was an outbreak of 17 tornadoes that struck the Southeastern U.S. on April 5-6, 1936. Nearly 420 people were killed by these tornadoes, with 216 deaths reported in Mississippi and 203 deaths in Georgia. Although the outbreak was centered around Tupelo, Miss., and Gainesville, Ga., other destructive tornadoes associated with the outbreak struck Columbia, Tenn., Anderson, S.C., and Acworth, Ga. Severe flash floods from the associated storms also produced millions of dollars in damage across the region.

Photo: This April 6, 1936, photo shows offices along South Main Street including The Gainesville News and N.C. White Photograph Studio in Gainesville, following three tornadoes that touched down in the early morning.

1 'Tri-State' Tornado (Missouri, Illinois and Indiana); March 18, 1925; 695 deaths from one tornado; 747 total deaths
Jackson County Historical Society in Murphysboro, Ill.

According to the National Weather Service, the single deadliest day that it is aware of was March 18, 1925, when tornadoes killed 747 people. The day also saw what weather officials believe was the single deadliest tornado when one twister ripped through Missouri, Illinois and Indiana, killing 695 people. The continuous 219-mile track left by the 1925 Tri-State Tornado was the longest ever recorded in the world: the tornado crossed from southeastern Missouri, through Southern Illinois, then into southwestern Indiana. While not officially rated by NOAA, it is recognized by many as an F5 tornado, the maximal damage rating issued on the Fujita scale.