The woodlands in today's Southern Belarus and Central-North Ukraine is the setting for a tale of terror. 30 years ago, on April 26, 1986 - in what was then the Soviet Union - Ukraine's Chernobyl Nuclear Power Plant in Pripyat - about 15km North of Chernobyl town - suffered a catastrophic reactor failure causing the worst nuclear accident in human history. 2 plant workers died that day, 28 or 29 more died within a few weeks due to radiation poisoning, fallout contaminated much land and the disaster also caused the relocation of thousands of people. Everybody within 30km were evacuated (Pripyat had 49,000 inhabitants, Chernobyl 12,500) by May 14th (World Nuclear Association) and at that time "within a 30km radius of the power plant, the total population was between 115,000 and 135,000" (World Nuclear Association).
Let alone the horror of fires, explosions and radioactive fallout for a moment, and imagine being told by the authorities you must leave your home for 3 days and you can only take the essentials, but it turns out to be forever and you can never collect your things or return home due to contamination fears.
I'm not a nuclear physicist and I'm not a science-know-how guy, so if you want to know more about what caused this reactor failure, then visit the World Nuclear Association. I find the results of the accident more comprehensible. In addition to the aforementioned, the disaster also caused radioactive release to go into the environment for 10 days before the source was contained; Ukraine and Belarus absorbed most of the contamination, but it also reached Russia and other parts of Europe with the help of wind. It's a true nightmare what happened, and it could have been much worse for Europe if the release was greater. Thank God it wasn't.
There are many problems in trying to calculate the number of victims that died later - due to radiation-created sicknesses, cancers and a plethora of other health complications associated with radiation - but some reports say "the eventual death toll could reach 4000" (Wikipedia). Furthermore, it cost the Soviet Union 18 billion rubles (U.S. $18 billion at the time) "to contain the contamination and avert a greater catastrophe" (Wikipedia) and it still costs effected countries money in health care for those effected; moreover, the meltdown was a major contributing factor in the collapse of the Soviet Union only 5 years later as it basically led to their bankruptcy.
Again, I'm not a physicist, so I can't tell you what is radioactive and what is whatever. What I know is that there is a large pile of radioactive gunk - be it water, particles or whatever - it's deadly to humans and can't simply be thrown away. The solution they came up with in 1986 was to build a concrete sarcophagus that covered the nuclear gunk and sealed it ... temporarily. This sarcophagus has a 30 year lifespan (to 2016) and a new sarcophagus (currently under construction and called the New Safe Confinement) will replace the old one and continue to contain this radioactive mess.
Unknown at the time, but a reality today, is that the Chernobyl Nuclear Power Plant, Pripyat and indeed the entire Chernobyl Exclusion Zone are now tourist attractions. I can't speak for others, but I can tell you that I visited this place in November 2013 because I wanted to see something unique. What I got was certainly different, but also morbid. Seeing the decrepit ruins of a city hastily evacuated; seeing the neglected amusement park, homes, stadium and more, all now overgrown by Nature and reminiscent of a post-nuclear war movie or some zombie apocalypse flick; as a teacher for most of my adult life, visiting the ruins of a school was personal; holding a Geiger counter and reading radiation; passing through a radiation detection machine; seeing all this devastation caused by human beings is without doubt unique, but it's also scary to see what man is capable of.