Full transcript: Former President George W. Bush speaks at 9/11 memorial ceremony

Former President George W. Bush spoke at the Sept. 11 memorial at Shanksville, Pennsylvania, to mark the 20th anniversary of the attacks Saturday.

Former President George W. Bush spoke at the Sept. 11 memorial in Shanksville, Pennsylvania, to mark the 20th anniversary of the attacks Saturday. The memorial commemorates the crash of United Flight 93, one of four commercial airplanes hijacked in the September 11 attacks. The plane crashed into a field after passengers fought with and overcame the hijackers. All aboard, including 40 crew and passengers, perished. Bush, who was in office at the time, reflected on the bravery of those passengers and the unity and heroism that took place in the days after the attacks, while warning about the lingering threat of terrorism, both foreign and domestic. He was joined by former First Lady Laura Bush, Vice President Kamala Harris, former Vice President Dick Cheney, Pennsylvania Gov. Tom Wolf, U.S. Interior Secretary Deb Haaland and others.