Watch ABC World News Tonight With David Muir with Fubo for $0 Today

David Muir, former anchor of "ABC World News" weekend edition, 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.