additional proof of the vaccine's safety. what this could mean for vaccine mandates moving forward. what new york city has done. and companies, too. the united airlines tonight giving employees five weeks from today to be fully vaccinated. and all of this comes as more than 180,000 children get covid in just one week. dr. jha standing by, answering questions on all of this and the booster and when you should plan to get it. also tonight, the mass evacuations and the race against time in afghanistan. will president biden extend that deadline? what the white house said just today. the taliban now saying that date is a red line. and the pentagon tonight on the u.s. military going into kabul to help americans and afghans get out. ian pannell reporting from kabul and martha raddatz live in washington tonight with what she's now learned. deadly weather here at home. the flooding tragedy in tennessee. many families say it came out of nowhere. at least 21 people now killed,