Shortly after midnight on March 24, 1989, the oil tanker Exxon Valdez struck Bligh Reef just off the coast of Alaska, dumping more than 11 million gallons of crude oil into the pristine environment.

Charity Hospital was one of the last hospitals to be evacuated after Hurricane Katrina hit. After five days without power or assistance, the staff of Charity took matters into their own hands — including orchestrating a risky roof evacuation — to care for their patients.

Five days after Hurricane Katrina trapped nearly 300 residents in their apartment building, known as The American Can, former recon Marine John Keller fought off looters, swam through floodwaters, and hot-wired boats to help guide them to safety.

Robert Green lost his mother and granddaughter when his Ninth Ward home was lifted off its foundation and floated down the street in the aftermath of Hurricane Katrina. After rebuilding several years later, Green has made it his life’s mission to bring the Ninth Ward residents back and rebuild their historic community.

Find out how a hurricane forms--and what makes it so dangerous.

What was the true purpose of Stonehenge? Bones excavated from the site suggest it may have been used as a temple for the dead.

The Greek island of Santorini lies above a dangerous volcano that could be fatal at any moment.

When Angela Trahan and her family were trapped in their own kitchen by floodwaters from Hurricane Katrina, Brother Ronald Hingle, a member of their school community, braved the winds and rising waters to bring them to safety.

The Great Blizzard of Feb. 23, 1888, saved lives and spurred advances in forecasting and emergency management, reshaping disaster response.

Viewing a solar eclipse is one of the most magnificent of natural phenomenons. Why do they happen?

Throughout its history, the U.S. has endured many devastating hurricanes. These are the deadliest hurricanes in American history.

Theo Wilson time-travels back to 1889 to the bucolic river shores of Johnstown, Pennsylvania, where the biggest flood in U.S. history is about to be unleashed.

At first, hurricanes were only given women's names -- until some women protested and got storms named after men, too.

U.S. Coast Guard rescue swimmer Laurence Nettles describes helicopter rescues and details how the Coast Guard prepared for Hurricane Katrina.

This clip from "History Uncut" provides aerial video of New Orleans, taken from a news helicopter, shortly after Hurricane Katrina. This provides a unique perspective of the devastation that Katrina wreaked on the city.

New Orleans poet Shelton “Shakespear” Alexander performs an original poem about his experience taking shelter at the Superdome during Hurricane Katrina.

Find out where lava comes from and what happens when a volcano erupts underwater.

When Hurricane Katrina forced New Orleans poet Shelton Alexander to evacuate his home, he took his truck and video camera to the Superdome. He escaped the chaotic shelter a few days later with a truckload of people and video documentation of history.

Discover what made the Titanic a supersized ship.

When Hurricane Katrina hit the Gulf Coast, U.S. Coast Guard rescue swimmer Laurence “Noodles” Nettles’ training was put to the test as he and fellow Guard members were forced to adapt their ocean rescue tactics to save thousands of stranded victims from rooftops and rising floodwaters.

Survivors talk about the impact of Hurricane Katrina, 10 years after the historic storm devastated the Gulf Coast.

Find out how our national pastime may have saved lives during the San Francisco Bay Area’s deadly earthquake of 1989.

From crazy explosions to fast striking asteroids and even massive ice ages, planet Earth has had its life flash before its eyes a few times, see more in this episode of History Countdown.

Tsunamis are often called tidal waves, but they have nothing to do with tides.

Will solar eclipses eventually become a thing of the past? If so, when?

A look at how a period of climate change millions of years ago impacted evolution.