As Americans mourn and reflect on the 20th anniversary of the Sept. 11 terrorist attacks, the government remains focused on national security. Subscribe to GMA's YouTube page: https://bit.ly/2Zq0dU5 Visit Good Morning America's homepage: https://www.goodmorningamerica.com/ Follow GMA: Facebook: https://www.facebook.com/GoodMorningAmerica Twitter: https://twitter.com/gma Instagram: https://instagram.com/goodmorningamerica Watch full episodes of GMA: http://abc.go.com/shows/good-morning-america https://hulu.tv/2YnifTH SIGN UP to get the daily GMA Wake-Up Newsletter: https://gma.abc/2Vzcd5j #20thanniversary #terrorism #september11 #911 #warnings #dhs #fbi