Eugen Grigore case
1974 CE.
Shown on the map at 47.067°, 27.583°.
In July 1974, Romanian truck driver Eugen Grigore drove his cargo truck into a group of tents belonging to Romani nomads, killing 24 people and injuring 50 others. Grigore served approximately 27 years in prison. The case was not publicized at the time due to suppression by the Romanian state.
Text from the Wikipedia article Eugen Grigore case, licensed CC BY-SA 4.0.