Three Mile Island: The Meltdown That Changed America DESCRIPTION: In 1979, Unit 2 of the Three Mile Island Nuclear Plant experienced a partial core meltdown sparked by equipment failures and misleading control-room signals. The event caused national panic, prompted widespread evacuations, and exposed critical weaknesses in reactor safety. Though no immediate deaths occurred, the aftermath led to one of the largest nuclear investigations in U.S. history. The crisis forced major reforms in safety