President Trump walks with Melania Trump and National Parks and National Parks superintendent Stephen Clark through the Flight 93 National Memorial in Shanksville, Pa., on Tuesday.

President Trump walks with  Melania Trump and National Parks and National Parks superintendent Stephen Clark through the Flight 93 National Memorial in Shanksville, Pa., on Tuesday.

President Trump walks with Melania Trump and National Parks and National Parks superintendent Stephen Clark through the Flight 93 National Memorial in Shanksville, Pa., on Tuesday.

President Trump walks with  Melania Trump and National Parks and National Parks superintendent Stephen Clark through the Flight 93 National Memorial in Shanksville, Pa., on Tuesday