It's been 32 years since the Chernobyl disaster, a nuclear reactor meltdown caused by a mix of design flaws and human error.
The event immediately killed dozens and scarred the lives of tens of thousands of people over the ensuing decades.
Chernobyl is still considered the worst nuclear accident in history — but it could have been much, much worse, if not for a so-called "suicide squad" of three brave volunteers.
Alexei Ananenko, an engineer, was the only person on the shift who knew the location of the release valves which were located under the plant.
Valeri Bezpalov, was an engineer and
Boris Baranov, was the shift supervisor.