SHOW: ABC World News Tonight

https://abcnews.go.com/WN

David Muir, former anchor of the weekend edition of `ABC World News,’ tackles the responsibility of helming the weekday report of breaking news, taking the chair previously held by other well-known journalists: John Daly, Frank Reynolds, Howard K. Smith, Harry Reasoner, Barbara Walters, Peter Jennings, Charles Gibson, Bob Woodruff, Elizabeth Vargas and - most recently - Diane Sawyer.