For the commemoration of the 9/11 attacks, President Obama also visited the Pentagon and Shanksville, Pennsylvania, on Sunday. At the Pentagon, U.S. Secretary of Defense Leon Panetta said the United States will never stop fighting after the Sept. 11 attacks.

Leon Panetta, U.S. Defense Secretary: “To this day, and by these memorials to each victim, we pledge to never forget the enemy that made this happen, why we fight them, and why we will never stop fighting them, to make sure that what happened here and in New York City and in that field in Pennsylvania never happens again.”