(AP) — A long-delayed cleanup proposal for a Montana community where thousands have been sickened by asbestos exposure would leave the dangerous material inside some houses rather than remove it, as government officials seek to wind down an effort that has lasted more than 15 years and cost $540 million. Details on the final cleanup plan for Libby, Montana, and the neighboring town of Troy were to be released Tuesday by the Environmental Protection Agency. Health workers estimate as many as 400 people have been killed and almost 3,000 sickened in Libby and the surrounding area by asbestos exposure. To guard against such accidental releases, Tuesday's plan will outline a series of institutional controls designed to educate residents and contractors about what to do if they encounter asbestos, according to state and federal officials.