Mammoth Mine Explosion

Historical marker location:

Scottdale, Pennsylvania

( Marker is at the intersection of Scottdale Dawson Road (Pennsylvania Route 819) and Hornertown Road, on the right when traveling south on Scottdale Dawson Road.)

Marker installed: 2000

Pennsylvania was the site of the deadliest nuclear accident in U.S. history. In 1979, a partial meltdown occurred at the Three Mile Island nuclear power plant in Harrisburg, Pennsylvania.