On May 18, 1980, Mount St. Helens erupted with a force equivalent to 1,500 Hiroshima atom bombs, shooting gas and ash 15 miles high and obliterating virtually everything within an eight-mile radius. Trapped in the disaster were six people, including scientists studying the volcano, an elderly resident who refused to be evacuated, and campers who thought they were outside the danger zone. These are their stories, relived and retold by the lucky survivors and the friends and family of the fallen.

For years, experts have warned that the Bay Area was due for a major earthquake, but no one knew exactly when or where it would strike. On October 17, 1989, the answer came with a fury. Measuring a massive 7.1 on the Richter Scale, the quake left large parts of San Francisco in ruins and hundreds of residents trapped under collapsed structures and burning homes. Witness the heart-pounding and heartbreaking rescue efforts made as we focus on five people fighting to survive the deadliest U.S. earthquake in over 80 years.

Oklahoma. May 3, 1999. A series of massive thunderstorms explode in the sky, spawning a mile-wide monster tornado that tears through 38 miles of urban landscape, destroying more than 4,000 homes, and claiming 36 lives. Discover the tragedy caused by the most violent twister ever recorded as we revisit the disaster through the eyes of those who were there, including a young mother and child trapped in their mobile home, a family taking shelter in their bathroom as their house is ripped apart, and a scientist battling to track the twister.

The new engineer who must find a path to safety on a burning oil rig. The dive supervisor trying to shield 11 men from deadly fumes and flames. Two off-duty scaffolders who must brave a 17-story dive into the North Sea. These are just some of the harrowing stories of the 226 men caught in the 1988 explosion at Piper Alpha. Witness their tales and see how a series of split-second decisions and tragic twists of fate will determine who survives history's deadliest offshore accident.

The 1945 attack on the USS Indianapolis by a Japanese sub was so sudden and violent, it sank the warship before there was even time to launch lifeboats.Tragically, the wait for rescue for those who survived would take far longer.Witness the worst sea disaster in U.S. naval history, which claimed the lives of 879 men,by followingthe fatesof a maverick Marine and his friend, a Bronze Star captain, and the battle-hardened commanding office.

On October 9, 1963, a massive landslide slammed into a dam reservoir, unleashing a six-billion-gallon wall of water onto an unsuspecting village. In less than five terrifying minutes, over 1,500 people were killed and a town was reduced to little more than mud and rubble. Revisit the 1963 Vajont Dam tragedy, one of the world's worst man-made disasters in history, through the firsthand accounts of those swept up in the calamity.