Three Mile Island accident: 40 years later | News | witf.org

Three Mile Island accident: 40 years later | News | witf.org: Beginning around 4 a.m. on March 28, 1979, a series of technical and human errors led to a partial meltdown inside the Unit 2 reactor at the Three Mile Island nuclear power plant near Harrisburg, Pennsylvania. Four decades later, the event remains the most serious accident in U.S. commercial nuclear power plant operating history.