At 9/11 commemoration, Trump praises 'Heroes of Flight 93'

President Trump, first lady Melania Trump and Stephen Clark, the superintendent of the National Parks of Western Pennsylvania, walk through the Flight 93 National Memorial in Shanksville, Pa., on Tuesday.
President Trump, first lady Melania Trump and Stephen Clark, the superintendent of the National Parks of Western Pennsylvania, walk through the Flight 93 National Memorial in Shanksville, Pa., on Tuesday.