In this July 2, 2021 photo, a traveler walks in Terminal 3 as a sign stating face coverings are required is displayed at O’Hare International Airport in Chicago. The leading U.S. airlines say that the rise in COVID-19 cases is hurting ticket sales and pushing back the recovery of the travel industry. American, United, Delta, Southwest and others reported setbacks in regulatory filings Thursday, Sept. 9. (Nam Y. Huh/AP)
