Mega Disasters

Some scientists theorize that mass extinctions happened on Earth 65 million years ago due to powerful megastorms known as hypercanes, reaching 20 miles into the stratosphere.

The Mediterranean Sea bursts through the Bosporus Strait 8,000 years ago, inundating a valley twice the size of Ireland in a flood of biblical proportions.

Scientists piece together evidence of a tsunami that may have ravaged the Mediterranean world around 6,000 B.C., sweeping away villages and killing an untold number of people.

The supervolcano Toba erupts on Sumatra 75,000 years ago, causing a sudden volcanic winter that shocks the climatic balance around the world.

Scientists and engineers sound an alarm that a catastrophic dam failure might be the next mega-disaster facing America; a dam gives way near Johnstown, Pa., killing 2,200 people in 1889.

Examining the potential for disaster in Las Vegas, if a railway accident befell nuclear waste being transported for permanent storage below Nevada's Yucca Mountain.

Scientists speculate about a repeat of an Aegean Sea incident, as when a huge volcanic eruption on Santorini 3,500 years ago caused a tsunami that wiped out Minoan civilization on Crete and prompted the Atlantis myth.

Researchers study a comet explosion 13,000 years ago that ignited a firestorm across much of North America and killed nearly every living thing, including the Clovis human culture.

A new theory suggests that a megastorm caused one of the largest floods in the history of the planet, creating the English Channel and turning Britain into an island separated from the continent of Europe.

Analysis considers the deadly implications if airborne anthrax were unleashed over the U.S. in a biological attack.

A scenario demonstrates the potential for disaster from a "runway incursion" at a busy airport; 583 people are killed when two airliners collide in the Canary Islands in 1977; 34 people die when two planes collide in Los Angeles in 1991.

A toxic chemical cloud from an industrial accident could jeopardize an entire community within minutes, putting the lives of thousands of people at risk; a cargo ship carrying ammonia nitrate explodes, killing 500 people in Texas in 1947.