happening now, a health emergency as the skies over new york and other new york cities are shrouded with heavy and toxic smoke. right now. millions of americans are at risk as wildfires in canada create the air-quality crisis here in the united states. also this hour, a former spokesman speaks a in a grand jury. we are tracking new information in the investigation in trump s backyard. mike pence is taking on trump as he launches the 2024 launch for the weight. now ready to answer questions from iowa voters in a live cnn town hall event later tonight. welcome to the viewers here in the united states and around the world. you are in the situation room. let s get to the top story tonight. tens of millions of americans suffering through some of the most dangerous air quality in decades. the team of journalists covering the crisis from hard- hit cities all across the east coast. let s go to our chief climate correspondent joining us from brooklyn, new york. give us the latest.