Thousands of visitors were told to evacuate a remote Minnesota wilderness area accessible only by boat as wildfires send dangerously heavy smoke over the U. S. Midwest and Northeast this week. More than 100 wildfires are burning in Canada, where a train crew in northern Ontario filmed themselves surrounded by flames before being safely evacuated. Winds are carrying the smoke southeast. Warnings about unhealthy air conditions Wednesday extended from Minnesota through Toronto and into New York...