A powerful explosion that tore through a central Tennessee ammunition plant on Friday morning has left 18 people missing. The explosion occurred at 7:45 a.m. at a plant owned by Accurate Energetic Systems, which produces explosives and demolition charges for the U.S. military. Read the story here: https://nyti.ms/490uQTh Subscribe: http://bit.ly/U8Ys7n More from The New York Times Video: http://nytimes.com/video ---------- Whether it's reporting on conflicts abroad and political divisions at