10 Most Destructive Storms

The U.S. central plains region -- nicknamed Tornado Alley -- suffers the highest frequency of tornadoes in the world [source: Tarbuck]. Many of these twisters leave death, injury and destruction in their wake, but one stands in a class by itself.

Sweeping out from southeastern Missouri on March 18, 1925, the Tri-State Tornado careened across the southern tip of Illinois before dissipating in lower Indiana. Remarkably, these three locales lie 219 miles (352 kilometers) apart, and the tornado traveled this distance in just three and a half hours [source: SEMP].

Typical tornadoes measure 500 to 2,000 feet (150 to 600 meters) wide and move at a speed of about 30 mph (45 kph). Generous estimates suggest they travel an average of 6 miles (10 kilometers) before petering out [source: Tarbuck]. The Tri-State Tornado achieved an average speed of 62 mph (100 kph) and topped out at 73 mph (117 kph). It covered more than 36 times as much ground as an average tornado. Some eyewitnesses reported its path as nearly a mile wide [source: NOAA].

Scientists today wonder if the Tri-State Tornado instead might have been a family of tornadoes spawned by a massive supercell storm, which would account for both its extremity and for the remarkably straight path it followed for 183 of its 219 miles [source: NOAA].

All told, the EF5 storm killed 695 people, 234 of whom lived in the town of Murphysboro, Ill., thereby setting the grim record for the most fatalities incurred by a tornado in a single U.S. city. In total, 2,027 people sustained injuries from the tornado's passage, and 15,000 homes were destroyed. Entire towns were obliterated [source: SEMP].

Next, let's look at a more recent storm that the world won't soon forget.

Often the severity of a natural disaster derives from the poverty, poor construction standards or population density of the area it strikes. As evidenced by both the 2010 Haiti earthquake and Hurricane Katrina in 2005, the poor are less healthy, less able to get out of the way of oncoming disasters, more likely to live in shelters that are vulnerable to natural forces and to lack the resources to deal with a disaster's aftermath.

On April 26, 1989, a tornado touched down in the Manikganj district of Bangladesh -- one of the world's most densely populated countries. It swept eastward from the Daulatpur area into the severely drought-stricken areas of Saturia and Manikganj Sadar, cutting a swath 10 miles (16 kilometers) long and 1 mile (1.6 kilometers) wide. Although its duration and extent weren't especially large, the twister obliterated every structure within a radius of 2.5 square miles (6 square kilometers) [source: Encyclopaedia Britannica].

In the course of its brief rampage, the storm destroyed more than 20 villages, gusting residents, homes and livestock away. It also pummeled the landscape with rain and hail, threatening what few crops had survived the preceding drought [source: Associated Press]. When the scattered residents were accounted for, the tornado was found to have caused nearly 1,300 deaths, making it the deadliest tornado in recorded history [source: Encyclopaedia Britannica]. In the aftermath, central Bangladesh fell victim to widespread hunger and disease [source: Reuters].

In a grimly ironic twist, the tornado appeared just hours after then President Hussain Muhammad Ershad called upon the nation to pray for rain [source: Associated Press].

Although the death toll from this furious storm wasn't a record-breaker, Hurricane Katrina's financial impact was incomparable, and the storm forever changed New Orleans and the Gulf Coast region.

Trouble began brewing in the Atlantic in August 2005, when the storm formed in the vicinity of the Bahamas and swept across southern Florida. Upon returning to open waters, Katrina strengthened into a Category 5 hurricane -- the highest Saffir-Simpson rating possible. In the 18 hours before landfall, it mellowed somewhat into a Category 3 storm.

A Category 5 hurricane produces sustained winds greater than 155 mph (249 kph), whereas a Category 3 pumps out winds at 111-130 mph (178-209 kph). Both are horrifying.

Katrina's size and reach were remarkable. Tropical-storm-force winds could be felt 161 nautical miles from the eye of the hurricane [source: Knabb].

For all of its remarkable winds, the aspect of a hurricane that frequently poses the greatest threat to life and property is its storm surge -- the upwelling of water caused by shoreward-blowing hurricane winds. Katrina's storm surge towered almost 30 feet (9 meters) in some places, and its effects registered throughout the Gulf Coast region. The combination of extreme storm surges and time-weakened levees caused severe flooding in New Orleans and the surrounding communities. At one point, roughly 80 percent of New Orleans lay underwater -- up to 20 feet (6 meters) deep in some places -- and it would be 43 days before the last of the deluge would recede, its progress slowed by the arrival of Hurricane Rita a month later [source: Knabb].

In all, Katrina spawned 62 tornadoes across the Southeast and killed more than 1,800 people in numerous states [sources: Johnson; Louisiana Department of Health]. Louisiana suffered the greatest number of fatalities. There and in Mississippi, the storm surge annihilated entire coastal communities.

Due to the complex interplay of lost jobs, missed revenue opportunities and destroyed businesses, the final financial toll of Katrina is nearly incalculable, but estimates place the total financial impact at $200 billion [source: Galvin].

In "Hamlet," shortly after Polonius' death, King Claudius remarks, "When sorrows come, they come not single spies/But in battalions." Terrible weather events too often illustrate this grim adage, piling one sorrow upon another; storms can lead to floods, which can lead to disease and pestilence, and so on.

After four years of drought, Iran must have been desperate for water in any form -- any, that is, but the weeklong February 1972 blizzard in which it arrived. The storm dumped 10-26 feet (3-8 meters) of snow in outlying areas of northwestern, central and southern Iran, cutting off roads, cables and telephone lines, and trapping 4,000 villagers beneath its freezing blanket [sources: NOAA News; Raein]. Elsewhere, two massive avalanches buried an estimated 8,000 people.

Temperatures dropped to minus 13 F (minus 25 C) in some areas, freezing pipes and worsening the water shortage [sources: Raein]. In isolated, snowbound valleys, flu spread with a vengeance, and in some areas approached a 100 percent infection rate [sources: Raein].

Initial fatality estimates approached 6,000, but later revisions reduced the count to an estimated 4,000 [sources: NOAA News; Raein; St. Petersburg Times].

Tragic as the blizzard was, the death toll in the next disaster, which nearly washed an entire town out to sea, was higher still.

On Sept. 8, 1900, Galveston, Texas, braved a storm of biblical proportions, the deadliest natural disaster ever to strike U.S. territory. The day before it struck, the island city, located just off the Texas coast in the Gulf of Mexico, was a place of 37,000 people and bright economic prospects; the next day, its population had dropped to 31,000, and the city had sustained millions of dollars in damage [source: The 1900 Storm].

A hurricane -- estimated to be a Category 4 -- slammed into the unprotected, low-lying island, bringing with it immense destruction. The consensus among researchers places Galveston death tolls at 8,000 to 10,000 people, with some estimates ranging as low as 6,000 or as high as 12,000. February of the following year saw remains still washing ashore.

The hurricane's 140 mph (225 kph) winds and 15-foot-high (4.5-meter-high) storm surge demolished 3,600 buildings [source: The 1900 Storm]. The whole island was submerged; by the time the waters receded, 12 city blocks -- three-quarters of the city -- had been washed away [source: Zarrella]. In the intervening hours, people struggled to stay alive, clinging to anything they could find above water.

As the citizens rebuilt their town, they tried to provide some protection against future sea-spawned disasters. The townspeople propped up buildings -- in some cases as high as 17 feet (5 meters) above their original elevation -- and raised the grade of the island. They also constructed a seawall 17 feet high and 10 miles (16 kilometers) long, which helped protect the city when another hurricane hit in 1961.

As horrifying as the Galveston storm and its aftermath were to the people of Texas, they were nothing compared to the devastation that struck Central America almost a century later.

If we measure the costs of storms in lives, property and the difficulty of recovery, then Hurricane Mitch is, across the board, one of the worst hurricanes ever to strike land.

On Oct. 26, 1998, within a few short days of its Caribbean birth, Mitch slammed into the northeast coast of Honduras as a Category 5. Not long afterward, it weakened and stalled on the coast, where it transformed into a sprawling engine of rain production. During this time, the storm achieved peak winds of 180 mph (290 kph) and deluged much of Central America, causing flash floods, avalanches and mudslides that destroyed coastal regions, particularly in Honduras. After ramping up once again to tropical storm levels, it struck Florida on Nov. 5, then died out over the Atlantic [sources: Encyclopaedia Britannica; Rohter].

Mitch's floods, mudslides and winds wrecked crops and wiped out population centers throughout Honduras and areas of Nicaragua, Belize, El Salvador, Guatemala and Mexico. It demolished hundreds of thousands of homes, blew and washed away residents, and obliterated harvests. More than 11,000 people lost their lives, most of them in Honduras and Nicaragua, and thousands more went missing [source: Encyclopaedia Britannica].

In Honduras, Mitch left a country with no clear path to recovery. With infrastructure destroyed and unemployment on the rise following the destruction of vital plantations, one of the poorest and most debt-laden nations on Earth was faced with locating $1.7 billion to get it back on its feet [source: Morgan].

Now let's go a little further back in time, when another large cyclone wreaked havoc in the Caribbean, amid an international power struggle known to Americans as the Revolutionary War.

The devastating death toll of the Great Hurricane of 1780 exceeds even that of Hurricane Mitch. An estimated 22,000 people perished between Oct. 10 and 16 in the eastern Caribbean, most of them in the Lesser Antilles, with the heaviest losses occurring on the islands of Martinique, St. Eustatius and Barbados [source: CDERA]. Beyond these casualties, it's estimated that thousands of French and British sailors perished when the intense weather plowed into their vessels [source: CDERA].

Although its exact strength remains unknown, anecdotal evidence leads modern researchers to conclude that the Great Hurricane was a Category 5 storm with winds in excess of 200 mph (320 kph). Some eyewitness accounts attest to the complete ruins of sturdy stone buildings and forts, to heavy cannons sent hurtling hundreds of feet and to trees having their bark ripped away.

We've made it this far, and we're entering the top three. Continue to the next page to read about how chains of events can amplify the destructive power of storms.

The rain-spawned tragedy that befell the Vargas coast in Venezuela in December 1999 demonstrates how too much rain can spawn a domino sequence of devastation, a gestalt of destruction greater than the sum of its parts. From Dec. 14-16, a storm poured a year's worth of rain down on the vertical slopes of the Sierra de Avila Mountains north of Caracas, triggering flooding and some of the most massive landslides and debris flows in world history [source: Wieczorek].

The subsequent devastation smashed more than 8,000 homes and 700 apartment buildings. It wrecked roads, telephone and power lines, and water and sewage systems, running up a total bill of around $1.79 billion [source: Wieczorek]. An estimated 30,000 people died, but only about 1,000 bodies were ever recovered; debris flows and floods buried many of the remainder or swept them out to sea [source: USAID].

When it comes to suffering destruction at the hands of severe weather events, some places are topographically and geographically worse off than others, as we'll see next.

The year before Bangladesh would become an independent nation by seceding from Pakistan, it was struck by a raging cyclone that caused chaos on its low-lying coastal delta.

Cyclones striking Bangladesh tend to cause immense devastation because the country's topography conspires to amplify their impact. Thus, the 1970 storm, nicknamed the Bhola Cyclone, proved to be one of the worst natural disasters in recorded history, even though it made landfall as only a Category 3 storm. Fatality estimates range from 300,000 to 1 million people, although most put the tally at closer to 500,000.

Bangladesh's delta is one of the most fertile croplands on the globe, with several rivers pouring silt and nutrients into its soil. Because of this, the region ranks among the most densely populated in the world, despite the inherent topographical hazards of living there. The danger stems from two main factors. First, a good portion of the country barely rises above sea level. Second, its rivers (three major and several smaller ones) and the shape of its coastline combine to draw water far inland, increasing the likelihood and severity of flooding.

Storm surges strike areas like Bangladesh with particular lethality, and they cause most of the fatalities and a good portion of the property damage from storms like the Bhola Cyclone.

That just leaves one. Now, let's look at the mother of all destructive storms in recorded history.

From the dawn of civilization to today, floods have caused more human deaths and wreaked more extensive devastation than any natural force. The same rivers that offer life and the promise of sustainable sustenance can, in a season of floods, wipe out the people who depend on them.

In a work cataloging deadly floods, China would rate its own chapter, if not its own book. The 1931 central China floods alone resulted in an estimated 4 million deaths and affected a quarter of China's population, making it one of the worst natural disasters in history and helping to earn the Hwang Ho, or "Yellow River," the nickname "China's Sorrow." In 1887, its floods killed 2 million people, and the 1931 and 1938 floods took the lives of almost 5 million [sources: Hudec; NOAA News]. However, these resulted from months or years of accumulating drought, rain and storms that combined to create conditions ripe for disaster, and thus didn't constitute a single storm; for similar havoc occurring as the result of a single weather event, we have to turn to 1975's Super Typhoon Nina.

Nina's unparalleled destructive power derived not from its winds but from the catastrophic flooding it triggered. Indeed, the typhoon had already spent most of its strength crossing Taiwan's central mountain range and had weakened to a tropical storm by the time it struck China [source: Weyman]. As it stalled over the mainland, Nina cranked out 42 inches (1,060 millimeters) of rain in 24 hours -- a year's worth of central China's precipitation, delivered in a day. The deluge collapsed the Banqiao Dam and destroyed more than 60 other dams along with it [source: Xinhua].

As the dams buckled, a 6.2-mile-wide (10-kilometer-wide), 9.8-23-foot-high (3-7-meter-high) wave blasted across the lowlands at speeds approaching 31 mph (50 kph), destroying an area 34 miles (55 kilometers) long and 9.3 miles (15 kilometers) wide [source: CCTV]. The floods swept tens of thousands of survivors downstream and submerged thousands of square kilometers of land, killing 26,000 people. An additional 145,000 later died of disease and famine (some estimates place the death toll closer to 230,000) [sources: Goldstein; Xinhua].

In all, Nina collapsed almost 6 million buildings and affected 11 million people, running up an economic toll of $1.2 billion [source: Weyman]. In lives destroyed, and physical and economic impact, Nina truly towers among other typhoons as our most destructive storm.

These 10 storms were major natural disasters that afflicted huge numbers of people. To learn more about the ferocious storms nature throws our way, visit the links on the next page.