Canadian wildfire smoke turns air hazardous in the US Midwest. Officials say stay inside

abcnews - Heavy smoke from Canadian wildfires is darkening skies in parts of the U.S. The smoke on Thursday reduced visibility for commuters from the Great Lakes to parts of the East Coast

AI Summary: Winds have carried thick smoke from large Canadian wildfires into the U.S. Midwest and Northeast, pushing air quality to hazardous levels. Public-health officials are advising residents to stay indoors, limit strenuous activity and heed local warnings as hospitals and clinics brace for respiratory cases. Yes, nature’s air purifier just went on strike.