Urycz massacre
1939 CE.
Shown on the map at 49.182°, 23.406°.
The Urycz massacre, which occurred on September 22, 1939, in the village of Urycz (nowadays Urych), stands as one of the most significant war crimes committed by the Wehrmacht during its invasion of Poland. On that day, between 73 and 100 Polish prisoners of war hailing from the 4th Podhale Rifles Regiment were confined to a barn and burned alive.
Text from the Wikipedia article Urycz massacre, licensed CC BY-SA 4.0.