Market Street Massacre
1948 CE.
Shown on the map at 39.846°, -75.358°.
The Market Street Massacre occurred on November 6, 1948, in Chester, Pennsylvania, United States. Eight people were killed and five were injured before the gunman, 38-year-old Melvin Collins, killed himself during police arrival.
Text from the Wikipedia article Market Street Massacre, licensed CC BY-SA 4.0.