The coronavirus has shut down much of American life as we know it. These numbers from the TSA spell out how sharply air travel dropped in the nation as the virus started to hit North America in March. The TSA is screening about 2 million less travelers each day now than it was at the same time last year. Take a look at the table dating back to March 4:As of Thursday, the United States has become the country with the most confirmed cases of COVID-19 worldwide. March 24: Detroit Metro Airport TSA employee tests positive for coronavirus (COVID-19)