Wakefield massacre
2000 CE.
Shown on the map at 42.500°, -71.076°.
On December 26, 2000, a mass shooting occurred at Edgewater Technology in Wakefield, Massachusetts, United States. Michael Morgan McDermott, an employee at Edgewater Technology, shot and killed seven of his coworkers. It is the deadliest mass shooting in Massachusetts history.
Text from the Wikipedia article Edgewater Technology shooting, licensed CC BY-SA 4.0.