Alex Perez reports from Minneapolis, where a gunman outside a Catholic school church's stained glass windows opened fire on students attending mass – killing an 8-year-old and 10-year-old and injuring dozens more – and Pierre Thomas has the latest on the disturbing details investigators have now learned about the shooter; Rachel Scott has details on the newly installed director of the Centers for Disease Control and Prevention, Susan Monarez, who has been ousted just weeks after being confirmed by the Senate; Victor Oquendo has the latest on the controversial Florida immigration detention center known as "Alligator Alcatraz" that will likely be empty within days, according to an email obtained by ABC News; and more on tonight's broadcast of World News Tonight with David Muir.

Morgan Norwood reports on the intense turbulence that rocked a Houston-bound United Express flight, sending two passengers to the hospital; as internal changes at the CDC spark a leadership crisis, Selina Wang has details on the FDA's new restrictions on COVID vaccines creating confusion over how and where Americans will get the vaccine; twenty years after Hurricane Katrina left a trail of pain and destruction along the Gulf Coast, Robin Roberts returns to the region to speak with the children impacted by the storm about the enduring emotional toll that's followed them into adulthood; and more on tonight's broadcast of World News Tonight.