On that day the world's worst nuclear accident happened at the Chernobyl power plant near the Ukraine/Belarus border.
The wind blew the aerosol of radio active particles over Belarus. Some reached the United Kingdom, and in parts of Cumbria and Wales even today lambs cannot be sold because their meat is contaminated.
70% of the fallout landed on Belarus. One third of the country was directly affected, polluting the land, the water supply and the food chain.
One quarter of the country's agricultural land was contaminated.