On April 26, 1986, Reactor #4 at the Chernobyl Nuclear Power Plant near the town of Pripyat, Ukraine, exploded. The explosion took place at 1:23am while the neighboring town of Pripyat slept. Two workers were killed instantly. 40 hours later, the residents of Pripyat were ordered to evacuate, and most never returned; by that time, many of the residents had suffered varying degrees of radiation poisoning.