On March 28, 1979, almost a decade before the Chernobyl nuclear disaster, a nuclear reactor at Three Mile Island experienced a partial meltdown.

On that day, a combination of malfunctions and human error unleashed radioactive gases into the environment around the Three Mile Island nuclear power plant in Pennsylvania.

The Three Mile Island partial meltdown was not as damaging as the nuclear crises at Chernobyl or Fukushima: Nobody died because of the accident, but 2 million people were exposed to small amounts of radiation, and 140,000 people evacuated the area.

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Early on March 28, 1979, a combination of electrical and mechanical malfunctions, as well as human error, unleashed dangerous radioactive gases into the environment around the Three Mile Island nuclear power plant in Pennsylvania.

The plant sits on Three Mile Island in Susquehanna River.

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