Perfect Disaster

At two miles wide and with wind speeds of more than 350 mph, a super tornado would reduce downtown Dallas to a war zone within minutes. Scientists say it could happen. When it does, a Dallas emergency city manager is forced to choose between making sure his family remains safe, or saving the lives of millions.

Beneath the boiling surface of the sun lies a force that could destroy crucial technology and electrical grids, throwing the modern world back to the Stone Age. With only hours to prepare, a New York City engineer struggles to convince the mayor to take an action that may save an entire country.

The Pacific breeds the biggest and most powerful hurricanes in the world. So far, the 7 million inhabitants of Hong Kong have escaped a direct hit. But a slight change in weather will send an emergency coordinator scurrying through the streets to make sure her city is safe while the super typhoon sets its sights on the island.

We saw what happened to New Orleans after the sea breached its levies. Could the same thing happen to London? The city is well protected against the power of a storm surge, but there is one weakness.

There is a point at which a wildfire becomes unstoppable, and a phenomenon is born that can destroy anything its path. The Australian city of Sydney faces this threat every year. For the men and women working at the forefront of fire science, the nightmare is about to begin.

It happened more than a decade ago: An ice storm brought the Canadian city of Montreal to its knees. Scientists now believe there is far worse to come. Strangely enough, the big freeze begins with a warm spell.