Dense fog advisories were lifted across portions of southern Louisiana on Tuesday morning, one day after deadly pileup collisions occurred along Interstate 55 amid a “superfog” that involved dense fog and wildfire smoke. #smoke #fog #superfog #i55 #louisiana #pileup At least 7 people were killed and more than two dozen others were injured after at least 150 vehicles collided along north and southbound lanes of the highway late Monday morning. AccuWeather Meteorologist Melissa Constanzer explains what causes superfog. READ MORE: bit.ly/40f3H8U » Subscribe now for more videos from AccuWeather: bit.ly/2TQgT0O Download the AccuWeather app: » iOS: apple.co/3gwaSnL » Android: bit.ly/3xpmwGw » AccuWeather is the world’s most accurate source of weather. But don’t just take our word for it. Find out how we make a difference in the lives of more than 1.5 billion people by people who care about the weather. » Check out more weather videos here: www....