Today, the nation mourned the nearly 3,000 lives lost on Sept. 11, 2001, in the deadliest terror attack on U.S. soil. We look at how Americans marked this somber anniversary. Stream your PBS favorites with the PBS app: https://to.pbs.org/2Jb8twG Find more from PBS NewsHour at https://www.pbs.org/newshour Subscribe to our YouTube channel: https://bit.ly/2HfsCD6 Follow us: Facebook: http://www.pbs.org/newshour Twitter: http://www.twitter.com/newshour Instagram: http://www.instagram.com/newshour Subscribe: PBS NewsHour podcasts: https://www.pbs.org/newshour/podcasts Newsletters: https://www.pbs.org/newshour/subscribe