Tadmor Prison massacre
1980 CE.
Shown on the map at 34.559°, 38.285°.
On June 27, 1980, a massacre was committed on the prisoners of the Tadmor Prison by the Syrian Defense Companies in revenge for an assassination attempt on Syrian President Hafez al-Assad, which took place the previous day. After the assassination attempt, on orders from the president's brother, Rifaat al-Assad, fighters from the Defense Companies militia flew into the prison in helicopters and began indiscriminately killing prisoners, ultimately killing an estimated 1,000 people.
Text from the Wikipedia article 1980 Tadmor prison massacre, licensed CC BY-SA 4.0.