Mount Rainier is a ticking time bomb that could dwarf the 1980 eruption of Mount St. Helens, sending massive lahars and mudslides toward the Seattle-Tacoma metropolitan area.

Cumbre Vieja, a volcano on the island of La Palma in the Canary Islands, off the northwestern coast of Africa, may potentially collapse in the future. If it does, a massive tsunami will be headed right for the East coast of the United States, threatening major cities like New York, Boston, Baltimore, and Miami.

The largest volcanic eruption of the past two million years occurred on the Indonesian island of Sumatra some 75,000 years ago. The impact from the supervolcano Mount Toba decimated the local habitat, but gas, ash and debris from Toba made their way around the planet and formed a shield in the atmosphere that deflected the sun's warming rays. Temperatures plummeted and the planet was thrown into a volcanic winter and may have even pushed the planet into an ice age. 3-D computer animation will recreate the storm and unveil how this one volcano could have brought humanity to the edge of extinction.

Methane gas precipitates out of the Earth's crust but is easily diluted in the air and in the oceans. Yet, according to one scientist, certain oceanic conditions could trap the gas in regions with low water circulation and build up extreme pressure. Once these areas are disturbed, the gas would blow out of the ocean in powerful jets. If they ignited before diluting, the explosion could cause widespread devastation. The scientist also posits that a similar event caused the Permian extinction.

Exploring the possibility that a hypercane (a theoretical super hurricane) may have hit Earth billions of years ago and destroyed most of the life on the planet.

Yellowstone National Park lies on top of a magma chamber that is 35-miles wide, waiting to erupt. (For further information, see Yellowstone Caldera.)

The United States faces a potential tsunami threat that mirrors the catastrophic Indonesia tsunami of 2004. Just west of the Oregon coast lies the Cascadia subduction zone where the Juan de Fuca Plate is moving under the North American Plate. A major earthquake here could displace enough water to cause a massive wave to impact along the west coast.

The possibility of a tornado hitting downtown Chicago is the scenario. Included is an examination of the 1967 twister that hit the suburb of Oak Lawn.

An asteroid hitting the Earth off the coast of Los Angeles is the scenario. Included: the theory that an asteroid strike may have been responsible for the extinction of dinosaurs.

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.

A comet is imagined to strike the Earth and cause major devastation.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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?

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.

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.