White flags are seen on the National Mall in Washington, D.C., the United States, on Sept. 16, 2021. More than 660,000 white flags were installed here to honor the lives lost to COVID-19 in the United States.Photo:Xinhua

White flags are seen on the National Mall in Washington, D.C., the United States, on Sept. 16, 2021. More than 660,000 white flags were installed here to honor the lives lost to COVID-19 in the United States.Photo:Xinhua