Top Story with Tom Llamas - June 23 | NBC News NOW

A severe weather system has millions of Americans under alert, questions are mounting about what caused the implosion of the Titanic submersible, and dozens of migrants feared dead in a sinking off the Canary Islands. » Subscribe to NBC News: » Watch more NBC video: NBC News Digital is a collection of innovative and powerful news brands that deliver compelling, diverse and engaging news stories. NBC News Digital features , , , Nightly News, Meet the Press, Dateline, and the existing apps and digital extensions of these respective properties. We deliver the best in breaking news, live video coverage, original journalism and segments from your favorite NBC News Shows. Connect with NBC News Online! NBC News App: Breaking News Alerts: Visit :