Jirí Chmelnicek shot this footage in just-liberated Prague on May 10, 1945 of Czechs celebrating the end of World War II by doling out mistreatment — including a chilling mass-execution — to Sudeten Germans. It was the presence of that population, the reader will recall, that Berlin invoked to justify its occupation of Czechoslovakia.

Chmelnicek’s video only surfaced publicly in 2010: its images were far too sensitive to air closer to the Great War, especially while Czechoslovakia was under communist control. As Der Spiegel reported.

Chmelnicek’s film shows how the Germans were rounded up in a nearby movie theater, also called the Borislavka. The camera then pans to the side of the street, where 40 men and at least one woman stand with their backs to the lens. A meadow can be seen in the background. Shots ring out and, one after another, each person in the line slumps and falls forward over a low embankment. The injured lying on the ground beg for mercy. Then a Red Army truck rolls up, its tires crushing dead and wounded alike. Later other Germans can be seen, forced to dig a mass grave in the meadow.

We do not know who these people are. Considering the indiscriminate revenge visited on Sudeten Germans after the war, it is not likely that these several dozen souls were selected for their fate with care.

On this day..

• 1682: Four at a Lisbon auto de fe
• 1942: Julius "Babe" Hoffmeister, alcoholic POW
• 1896: Five Persians by gatching
• 1643: The Book of Sports
• 1756: Owen Syllavan
• 1527: Johann Hüglin, Meersburg martyr
• 1794: Elisabeth of France, sister of the king
• 1956: Andreas Dimitriou and Michalis Karaolis, the first EOKA men hanged
• 1900: Three Algerians in Setif
• 1821: Stephen Merrill Clark, boy arsonist
• 1994: John Wayne Gacy, scary clown
• 1987: Sadamichi Hirasawa, by old age