Since commercial aviation truly began in the 1930s, the romance of air travel has been marred by the tragedy of crashes. Unless significant changes continue to be made in airport infrastructure, aviation technology, and professional training, any American airport could be the site of the next Mega Disaster.

As temperatures rise, a global meltdown has begun. From the Andes to the Himalayas to the Alps, glaciers are vanishing. In Antarctica and Greenland, vast ice sheets are turning into liquid. The melting ice, running off land, is raising sea levels. As sea levels rise, oceans throughout the world are also becoming hotter. Warmer seas fuel more intense hurricanes. Already, major catastrophes brought on by the process of melting ice, rising seas and intensifying storms have occurred in coastal communities around the world: the South Pacific, Bangladesh and—closer to home—New Orleans. Scientists predict that the worst is yet to come. The rising oceans may swallow some lands forever. By the turn of the century, the map of the world may need to be redrawn and a Category 4 hurricane could drown much of Washington, D.C. in 15 feet of water.

The shield volcanoes that make the Hawaiian Islands will erupt again and cause major destruction by earthquakes and massive lava flows.

Recalling the 1917 explosion of the ship Mont Blanc in Halifax Harbor, which left almost 2000 people dead and 6000 people homeless. Included: speculation about whether a similar disaster could occur in Boston Harbor.

An earthquake in New York City may seem like the plot of a bad movie, but a magnitude 5 quake occurred in 1884 and could happen again. Two faults run under Manhattan Island, including the 125th Street Fault where the landscape dips and the subway crosses on an open bridge. Since skyscrapers are designed to withstand windspeeds of 100 mph, most would survive sans windows; however, mid-sized masonry structures would collapse. As well, buildings (including smaller skyscrapers) built on landfill in Battery Park are subject to soil liquefaction, tipping over entirely in a major earthquake.

The oil that our world runs on won't last forever. The gap between supply and demand is ever increasing. Will alternative energy save us or is it already too late? What would happen to the world as we know it when our oil dependent industries come to a grinding halt? A worldwide depression is a certainty but a power struggle for the basic necessities of life would be complete chaos.

The U.S. Department of Energy and the Nuclear Regulatory Commission plan to transport 77,000 tons of nuclear waste to a permanent storage facility 950 feet below Nevada's Yucca Mountain. If the plan goes through, much of the cargo will travel through Las Vegas, making an accident there a very disturbing possibility. If history has taught us anything, it's that transporting dangerous goods can sometimes have catastrophic results. Take a look at the potential disaster that such a rail accident would have in Las Vegas.

Anthrax is the most feared of all the biological weapons--spores entering the body through the lungs are lethal. In 2001, a simple letter, sent through the US mail, paralyzed a nation, when anthrax spores were found inside. Experts predict that anthrax released over a populated area would result in unprecedented loss of life--a few pounds of anthrax released under the right conditions could kill hundreds of thousands of people. Will anthrax be used to create a worldwide disaster?

The Thera volcanic eruption nearly 4000 years ago at the site of what is now Santorini. Greece, and the resulting tsunami are recalled. Also: speculation regarding another possible eruption.

The locust is one of the most destructive and dreaded life forms on Earth. American pioneers faced the largest swarm of locusts ever recorded. The 1,800 mile long and 110-mile-wide cloud of insects ate their way through the heartland and blocked the sun for five days. Famine ensued, and thousands faced starvation. According to recent studies, the possibility of such a swarm returning to the United States is very likely. The destruction would be unimaginable. This scenario is now generally believed by entomologists to be impossible. The Rocky Mountain locust, the insect responsible for the aforementioned swarm, has not been sighted since 1902. Efforts to breed modern North American grasshoppers to recreate the locust have all failed, and recent mitochondrial DNA analysis has strongly suggested that the Rocky Mountain locust was a distinct species.

Could an alien infection cause an epidemic on earth? Some experts believe that spacecraft returning from Mars could bring back a harmful sample or comet dust falling into our atmosphere could cause pandemics. One astronomer believes that the 1918 flu pandemic, which killed between 50-100 million people, was one such outbreak and that another "infection" could decimate the world's population. Astrobiologists are now poised to bring Mars samples back to earth to examine them in a Bio 4 level safety lab. In a hypothetical future disaster scenario, track how comet dust would seed the earth with a virulent virus. Quarantine measures don't work and panic ensues.

It has been a century since the infamous 1906 San Francisco earthquake and Californians live with the knowledge that it's only a matter of time before they're hit again. Los Angeles is the second most populous city in America. If an earthquake hit directly beneath downtown LA, scientists believe that tens of thousands would be killed. Just how would the city respond to a 7.5 magnitude quake? Take a look at how well the emergency responders could cope. A CGI worst-case scenario will show the incredible damage and destruction that would cripple one of the most important cities in the world.

Around 65 million years ago, a massive asteroid crashed into Mexico's Yucatan Peninsula. Nearly 75% of all life on earth vanished. But could a single asteroid have been the lone killer? Theories about what happened after the impact have been speculated on by the entire scientific community. Ranging from global warming to lethal worldwide firestorms, ideas have been put forth, but none have been proven. Then in 1995 a new theory claimed that a powerful mega-storm known as a hypercane caused the extinction. The hypercane allegedly reaches 20 miles into the stratosphere and has wind speeds of up to 500 miles per hour. 3-D computer graphics will reveal how this storm could have brought down nearly all life on the planet.

Every few seconds, a supernova emits jets of deadly gamma rays somewhere in the galaxy. If one of these gamma ray bursts should happen sufficiently close to the solar system, all life would perish.

About 8,000 years ago, rain squalls had global oceans surging. The oceans rose above all of the earth. When the flood was over the Mediterranean Sea had claimed a landmass twice the size of Ireland. This prehistoric mega-storm was the greatest natural disaster in human history. 3-D computer animation will recreate what this lethal flood may have looked like.

Trends indicate that a major drought event is looming in the not-too-distant future. In as few as three decades we could experience conditions that would make the Dust Bowl of the 1930s seem like an oasis. Efforts to conserve, while admirable and desperately necessary, may already be too late. The episode projects a scenario seventy years into the future in which a twelve-year drought leaves the United States unstable and economically depressed. Western cities are abandoned, states clash for dwindling water supplies and society devolves into a battle for survival.

In 6,000 BC, 8,000 years before the 2004 Indian Ocean tsunami, a paleotsunami whose waves reach taller than the Statue of Liberty allegedly was generated by a landslide from Mount Etna and ravaged the coasts of the Mediterranean Sea, devastating ancient villages and killing untold numbers. A team of scientists pieces together evidence of this megatsunami and reveals the face of this ancient tsunami for the first time. 3-D computer generated animation recreates the massive waves that may have changed the course of history.

This special-edition episode examines what happened in the 1906 San Francisco earthquake and its effect on San Francisco and looks at the destruction if it were to happen again today.

In AD 79, Mount Vesuvius buried Pompeii and killed 5,000 people. The volcano is quiet at the moment, but the only consistency in Vesuvius' eruptive history is a lack of consistency. The danger zone that surrounds the volcano includes the city of Naples and its one million residents; another two million people reside nearby. Scientists know that when Vesuvius erupts again they won't have much warning and another major metropolis will be destroyed.

How a major tornado would impact Dallas is examined by studying the effect of a twister that struck Oklahoma City on May 4, 1999, killing 43 people and causing $1 billion in damage.

A Category 3 hurricane hitting New York City is the scenario. Included: a history of hurricanes in the Northeast; and the origins of such storms.

The Hurricane Katrina disaster is studied as a model to examine what might happen if Sacramento's levee system failed and a similar tragedy resulted.

Modern dams are marvels of engineering but after decades of neglect the U.S. infrastructure is in crisis and by 2020, 85% of U.S. dams may be near their breaking point. When the South Fork Dam near Johnstown, Pennsylvania gave way in a storm in 1889, killing 2200 people, it was the worst disaster in U.S. history. Today, with millions of Americans living nearby massive dams, the result of a failure could be catastrophic.

The 1883 eruption of Krakatoa was one of the deadliest natural disasters in recorded history, claiming over 36,000 lives by the tsunamis it triggered. Another volcanic eruption at Krakatoa, now called Anak Krakatau (meaning "Child of Krakatoa" in Indonesian), could spell curtains for Indonesia.

The possible effects of extreme climate changes around the world in a short period of time are examined. Included: how drought altered the Mayan civilization.