In March 1979, a major nuclear accident occurred at the Three Mile Island Nuclear Generating Station near Middletown, Pennsylvania, United States. It was one of the most significant nuclear accidents in the history of the United States. The accident was caused by a series of equipment failures, operator errors, and design flaws that led to a partial meltdown of the Unit 2 reactor's core. While there was no immediate loss of life or widespread health effects, the incident raised concerns about nuclear safety and had a significant impact on public perception of nuclear power in the United States.