At 01:23:40 on 26 April 1986, the failure of a routine test at the Chernobyl Nuclear Power Plant in Ukraine, then part of the Soviet Union, caused reactor 4 to explode, releasing parts of its radioactive core. It was the worst nuclear accident the world had ever seen, with far-reaching political, economic and ecological consequences. Thirty-five years on, Chernobyl is still as well-known as it was a generation ago.
Fires broke out, causing the main release of radioactivity into the environment. Wind carried contaminated particles over Ukraine, Belarus and Russia, as well as parts of Scandinavia and wider Europe. The 50,000 inhabitants of the adjacent town of Pripyat were evacuated, never to return.