Women dancing at the disco club Xenon in New York City, USA in 1978. Xenon was a popular disco in Manhattan in the late 1970s and early 1980s. It was the only nightclub popular enough to compete with Studio 54. (Photo by Waring Abbott/Getty Images)

German troops in Stalingrad, USSR. September 10, 1942. (Photo by TASS)

Ammunition airlift into besieged Khe Sanh, Operation Pegasus, April 1968. (Photo by Larry Burrows/AP Photo)

German Nazi leader Adolf Hitler (1889 - 1945) enjoys a quiet picnic between meetings, circa 1933. Picture 196 of a series of collectable images published in Germany during the Nazi period, entitled “Deutschland Erwacht” (Germany Awakes). (Photo by Heinrich Hoffmann/Hulton Archive/Getty Images)

An air raid drill at Seattle College caught students William Bates, left, and Edna Mae Farrell, right, while they were eating their lunch in the school café, but they simply took shelter under the table and continued eating in Seattle, Washington, March 17, 1942. Air raid wardens said 350 students left their classrooms and assembled in shelters within one minute in first at the college. (Photo by AP Photo)

Gunfire was brought to the steps of President Truman's Washington home, Blair House, as two assassins tried to kill the chief executive, November 1, 1950. One of the gunmen, Oscar Collazzo of New York, lay wounded at the bottom of Blair House's front steps after the president's police guard had finished their work, at the cost of one guards' life, Dec. 9, 1950. The second gunman was killed. (Photo by Harvey Georges/AP Photo)

Long row of shiny new Flying Fortresses, part of huge reserves being built up in Britain for D-Day, stands by to be flown to combat units as replacements, May 25, 1944. (Photo by AP Photo)

Adolf Hitler (left), German Nazi politician, in a deck chair next to is niece Angela (Geli) Raubal – around 1930. (Photo by Ullstein Bild/Ullstein Bild via Getty Images)