9/11 families react to killing of al Qaeda leader Ayman al-Zawahiri
President Biden announced the U.S. killed al Qaeda leader Ayman al-Zawahiri in a drone strike in Afghanistan, and said "justice has been delivered" for families of 9/11 victims. Alice Greenwald, President and CEO of the National 9/11 Memorial and Museum, joins CBS News to discuss how victims' families are reacting to the news.