August 23 at 8 p.m.
Devastating hurricanes struck the U.S. mainland and Caribbean islands in 2017. But they weren’t the first. The Great Hurricane of 1780 took nine days to blast its way across the Caribbean, killing at least 20,000—the highest known death toll of any single weather event in history. What made this superstorm so deadly?
August 23 at 9 p.m.
All over the world, scientists are discovering traces of ancient floods on a scale that dwarfs even the most severe flood disasters of recent times. What triggered these cataclysmic floods, and could they strike again? In the Channeled Scablands of Washington State, the level prairie gives way to bizarre, gargantuan rock formations: house-sized boulders seemingly dropped from the sky, a cliff carved by a waterfall twice the height of Niagara, and potholes large enough to swallow cars.