In June 1969, Dennis Lloyd Martin walked off to play a prank on his dad and never returned, sparking the largest search effort in the history of Great Smoky Mountains National Park.

In 1944, Finnish soldier Aimo Koivunen got separated from his unit and survived for weeks inside the Arctic Circle without food or shelter — fueled by a dose of meth large enough for 30 men.

Just days after her 24th birthday in August 2015, Alison Parker and 27-year-old cameraman Adam Ward were murdered in the middle of an on-air morning interview which was broadcast in real time.

Known as the "eighth wonder of the world," the Amber Room at the Catherine Palace in St. Petersburg was looted by the Nazis and disappeared forever in 1943.

Jane Wilde and Stephen Hawking married in 1965, shortly after Hawking learned that he had motor neuron disease. As his illness progressed, his wife became his primary caregiver.

Known among the Nazis as "the girl with the red hair," 24-year-old Hannie Schaft was so deadly that Adolf Hitler personally ordered her capture.

In 1919, Black sharecroppers in Arkansas tried to organize for better wages — until a white mob and U.S. troops murdered hundreds of them.

Also known as Canities subita, Marie Antoinette Syndrome is the name for a mysterious condition said to suddenly turn all of your hair white due to fear or stress — but the scientific jury is still out on whether or not it’s real.

"Princess Caraboo" was actually Mary Baker Willcocks, an English cobbler's daughter who fooled an entire town near Bristol, England into believing she was royalty from the Pacific island of "Javasu."

The Pullman Strike of 1894 saw more than 250,000 railroad workers walk off the job and halt the U.S. economy for months — until federal troops were called in.

Joe Rosenthal's "Raising the Flag on Iwo Jima" captured one of World War II's most iconic moments, but the real story behind the photo would remain little-known for decades.