This Day In History: 04/23/1564 - William Shakespeare Born

Japan escalates its war in China, drawing increasing U.S. sanctions and widespread outrage. Driven by resource shortages and military ideology, Japan attacks Pearl Harbor in a move that will reshape the course of World War II. See more in this clip from Season 1, Episode 4, "Pearl Harbor."

The story of how America’s battle to control the seas against the terrifying German U-boats in the Atlantic and Japan’s fearsome Navy in the Pacific ultimately turns the tide of the war. See more in this clip from Season 1, Episode 5, "The War at Sea."

The reactor at the center of the Chernobyl disaster was one of the most powerful machines ever built. But it contained a series of design flaws that made it uniquely vulnerable under the wrong conditions.

On April 26, 1986, a routine safety test at the Chernobyl Nuclear Power Plant spiraled into the worst nuclear disaster in history. But the explosion wasn't caused by a single mistake—it was a series of catastrophic mistakes.