On April 26, 1986, a nuclear reactor accident occurred at the Chernobyl Nuclear Power Plant in the former Soviet Union. An explosion and fire released catastrophic levels of radiation into the atmosphere over much of the Western USSR and Europe. The cost to contain the spread of the radioactive particles was enormous. The official Soviet count for fatalities was 31, but that number has been widely disputed and is thought to be much higher. And cancers and deformities from the disaster are still being accounted for. It was the worst nuclear diaster in history.
Here are newspaper headlines from way back then: