Thunder Bay – For more than 100 years, the pulp and paper mill in Dryden has been the most important building in this small city in northwestern Ontario. It was the engine of the local economy, providing jobs for generations and connecting Dryden to a larger network of forest products that includes Thunder Bay and other communities in the area. But the same industrial complex also caused one of Canada’s worst environmental disasters. In the 1960s and 1970s, a chlor-alkali plant that was part of the mill dumped an estimated 9,000 to 10,000 kilograms (about 10 metric tons) of mercury into the English–Wabigoon River system. …People have lived with symptoms of mercury poisoning for generations, including Minamata disease. Commercial fishing was stopped, and guiding jobs disappeared. The main question is still painfully unanswered decades later: Who should pay to clean up the river, fix the land, and help the people who were hurt?