In the early morning of April 26, 1986, several explosions destroyed Reactor 4 at the V.I. Lenin Chernobyl Atomic Energy Station in Ukraine. Over 100 radioactive elements including Iodine, Cesium, Strontium, and Plutonium were released into the atmosphere.
During the ensuing days, rescue and cleanup workers (liquidators) were exposed to massive doses of radiation. Due to the enormous release of radiation, the Soviet government evacuated over 100,000 people from a large area surrounding the plant. To this day and through the foreseeable future, the area is considered too dangerous for human habitation, though normal radiation levels have returned to some locales.
After the disaster and subsequent decontamination efforts, the Soviet government established boundaries for the newly created Chernobyl Exclusion Zone encompassing portions of Ukraine and Belarus. The Zone is located within 30 km of the station and access is strictly controlled by the Ukrainian and Belarusian governments and militaries.