April 26th is the 20th anniversary of the most horrific nuclear accident in history, when the Chernobyl reactor in Ukraine blew up during a routine test, blasting the 1,000-pound roof of the main reactor building into the air and spreading radioactive waste over much of the northern part of the country and nearby Belarus. Some parts of the Chernobyl region will be contaminated with hazardous levels of radioactivity for 100 years or more, and residents have suffered from high levels of cancerous tumours and other birth defects. Photographer Robert Knoth has documented some of the victims in a photo essay. To see more, click on the picture.