The Lattimer massacre was the violent deaths of at least 19 unarmed striking immigrant anthracite miners at the Lattimer mine near Hazleton, Pennsylvania, United States, on September 10, 1897. The miners, mostly of Polish, Slovak, Lithuanian and German ethnicity, were shot and killed by a Luzerne County sheriff's posse. Scores more workers were wounded. The massacre was a turning point in the history of the United Mine Workers (UMW).