Families of the 67 people who died in January's midair collision between an American Airlines regional jet and an Army helicopter over Washington, D.C., are set to gather for a congressional hearing looking into the tragedy. The heads of the FAA, the NTSB and Army Aviation set to testify about what went wrong. NBC’s Tom Costello reports for TODAY. » Subscribe to TODAY: youtube.com/@TODAY About: TODAY brings you the latest headlines and expert tips on money, health and parenting. We wake up every morning to give you and your family all you need to start your day. If it matters to you, it matters to us. We are in the people business. Subscribe to our channel for exclusive TODAY archival footage & our original web series. Connect with TODAY Online! Visit TODAY's Website: today.com Find TODAY on Facebook: facebook.com/today Follow TODAY on Twitter: twitter.com/TODAYshow Follow TODAY on Instagram: instagram.com/todayshow » Stream...