David Muir reports from Vatican City on the historic conclave ritual underway with 133 cardinals closed off from the world.

David Muir reports from the Vatican after the historic election of the first American pope. Less than 24 hours after being introduced, Leo XIV entered the Sistine Chapel to celebrate his first mass and spent time with the faithful, giving out blessings; Terry Moran reports on what the other American cardinals say happened inside the conclave that made history; Gio Benitez has the latest after radar screens went black again at Newark Liberty Airport for about 90 seconds on Friday. Just last week a similar radar outage forced the airport to cancel and delay thousands of flights, and more on tonight's broadcast of World News Tonight with David Muir.