Former President George W. Bush and former Secretary of State Condoleezza Rice said they initially thought the U.S. military had shot down United Airlines Flight 93 before it crashed in Pennsylvania during the 9/11 terrorist attacks.

Both political figures reflected on where they were on Sept. 11, 2001, ahead of the 25th anniversary, as they sat down for a conversation in remembrance at the George W. Bush Presidential Center in Dallas, Texas.