Vice President Mike Pence and his wife, Karen, tour the Flight 93 National Memorial on the 16th Anniversary ceremony of the September 11th terrorist attacks, September 11, 2017 in Shanksville, Pennsylvania. United Airlines Flight 93 crashed into a field outside Shanksville, PA with 40 passengers and 4 hijackers aboard on September 11, 2001. Jeff Swensen/Getty Images/AFP