concerns about united states joint military drills with south korea. panic on the new orleans parade route. a gunman opened fire. mardi gras back to pre-pandemic levels. e policeorbr n an arrest in connection with the catholic bishop shot at home. woman killed in an alligator attack in a florida retirement community. what i have to say tonight doesn t come from here. it comes from here. norah: good evening and thank you for joining us as we begin a new week together. tonight cbs evening news goes in-depth with a look at how americans are exposed to chemicals in our food. plus the story of 281-year-old best friends who are in the middle of a once-in-a-lifetime trip around the world. first, the story, the top-secret historic trip. security was tight as it was the first time in modern history that an american president traveled to a war zone where there is not a u.s. military presence on the ground. president biden s motorcade slipped out of the white house at