The Chernobyl accident, which occurred in the former Soviet Union in April, 1986, caused many problems. Nearly 3 million acres of farmland in the Ukraine were rendered useless for decades. Thirty-one workers died directly from the accident, while another 130 became sick. Many others in neighboring countries, like Switzerland and Poland also became sick. What type of accident was Chernobyl, considered to be one of the worst of its kind?