The years since the attacks of Sept. 11, 2001, have seen a lot of changes in the cultural fabric of the United States and in the armed forces. With the 20-year anniversary of that tragic day, it’s important for us to look back and remember some of the heroes that emerged from the ashes of the World Trade Center, the Pentagon, and United Flight 93. One of those heroes was a civilian named Todd Beamer. Beamer died when United 93 crashed in a field near Shanksville, Pennsylvania. But his memory...