The Sun Set Off 4,000 Sea Mines During the Vietnam War

(via Atlas Obscura)  On August 4, 1972, near the North Vietnamese port of Hai Phong, dozens of mines hiding in the waters exploded in little more than an instant. American troops had laced the seas bordering North Vietnam with thousands of mines, lying in wait for ships to pass by. But in this case, no ships had set them off.