STORY: How did the Chornobyl nuclear disaster happen?
On April 26, 1986
the fourth reactor at the nuclear plant in then-Soviet Ukraine
exploded during a botched safety test
sending clouds of radiation across much of Europe and reaching the eastern U.S.
It was the world's worst nuclear accident that killed 31 people right away and forced tens of thousands to flee their homes
Up to 115,000 people are thought to have died of radiation-related illnesses such as cancer, though estimates vary
The defunct power plant is still surrounded by miles of radioactive land
Russian forces occupied Chornobyl
soon after invading Ukraine on February 24, 2022
but left on March 31