What kind of damage happend at three miles island?

The Three Mile Island accident, which occurred in March 1979 in Pennsylvania, involved a partial meltdown of the reactor core in Unit 2. A combination of mechanical failures, design-related problems, and operator errors led to the release of a small amount of radioactive gases into the environment. Fortunately, the containment structures held, preventing a catastrophic release, and there were no immediate injuries or deaths. The incident significantly impacted public perception of nuclear energy and led to changes in regulations and safety protocols in the industry.