Authorities are investigating the deadly crowd surge in South Korea that left 154 people dead, including two American students, 20-year-old Anni Gieske and 20-year-old Steven Blesi. WATCH FULL EPISODES OF WORLD NEWS TONIGHT: https://abc.com/shows/world-news-tonight WATCH WORLD NEWS TONIGHT ON HULU: https://bit.ly/3iQLwPp #WorldNewsTonight #southkorea