Chernobyl. On April 26, 1986, reactor number four at the Chernobyl plant in the Ukrainian Soviet Socialist Republic suffered a meltdown. About 50 plant workers and firefighters died initially after heavy radiation exposure. The radiation plume spread, forcing large areas of Ukraine, Belarus, and Russia to be evacuated. Today, the Zone of Alienation, as the 19 mile exclusion zone around the plant is known, has been largely reclaimed by nature, with wildlife flourishing. This 2006 photo shows an amusement park in Pripyat, Ukraine, a city of 50,000 that was completely evacuated 36 hours after the meltdown. Residents were told they were being taken away for just 3 days.