Democratic presidential nominee Joe Biden on Friday commemorates the 19th anniversary of the Sept. 11, 2001 attacks in Shanksville, Penn. Subscribe to The Washington Post on YouTube: https://wapo.st/2QOdcqK Follow us: Twitter: https://twitter.com/washingtonpost Instagram: https://www.instagram.com/washingtonpost/ Facebook: https://www.facebook.com/washingtonpost/