When a nuclear plant goes into meltdown, it can lead to some of the most devastating disasters in human history. In this video, Unveiled discovers exactly what happens inside an exploding nuclear reactor - including at the three most famous meltdowns of all time; Fukushima, Three Mile Island and Chernobyl...

Some things are memorable for all the wrong reasons. From mass shootings, to widespread disease, to unthinkable disaster, these events had everyone breathless. WatchMojo counts down Another Top 10 Events That Made the World Stand Still.