Massive natural disasters have shaped the planet on which we live for millions of years, and the only thing we know for sure is that the future holds more. Earthquakes have triggered massive tsunamis and released methane gas that killed most of the life in the ocean. Asteroids have laid waste to nearly all the life on earth. Volcanoes have blocked the sun's rays for months. How would today's world hold up to such fury? As the devastation caused by Hurricane Katrina and the 2004 Indian Ocean tsunami have dramatically demonstrated, we are all vulnerable to unexpected disasters, both natural and man-made. Combining science and history, Mega Disasters visits the sites of previous disasters, then recreates them in modern times and locations, using state-of-the-art computer animation. Whether it's the city of Memphis crashing into the Mississippi River during an earthquake or a mile-wide asteroid destroying Los Angeles, each week is a hair-raising look at just how vulnerable our complex society really is to the power of Mother Nature.