Last week was the 20-year anniversary of the most serious civilian nuclear power accident in human history: the meltdown at Chernobyl.
1986-2006 is a site with some pretty amazing photographs of the deserted city, the reactor site, and so forth.
I am an ardent supporter of nuclear energy as a power source; one of the big lessons of Chernobyl is that, although it was a screaming horror ecologically, it wasn't nearly as bad as some of the dire predictions. The only people who provably died as a direct result of the accident were the firefighters and technicians working at the site, though there is good evidence that (for example) the thyroid cancer rate in the immediate area has gone up significantly.
Another of the big lessons is that, in competent hands, nuclear power accidents don't occur. Chernobyl was a "perfect storm" of design flaws, disregard for safety procedures and poor communication.