Disney Celebrates America

David Muir anchors a special edition of World News Tonight, as the United States celebrates its 250th birthday; Whit Johnson has more on the celebrations across the country, the tall ships and military flyover in New York City, and the extraordinary images of the day; Mary Bruce has details on Pres. Trump's address to the nation from the National Mall; Matt Rivers reports on the dangerous heat and deadly storms and Lee Goldberg has the forecast after lightning and damaging winds struck New York City overnight; and more on tonight's broadcast of World News Tonight with David Muir.