He describes being in the Pentagon when the hijacked American Airlines Flight 77 slammed into it on September 11 , 2001 . He recounts staying at his post amid the rubble and groping to determine the significance of the attack . He also remarks that the targeted sectors of the Pentagon were undergoing refurbishment ( with many offices unoccupied ) and thus many lives were spared
American Airlines Flight 77
American Airlines Flight 77
Known and Unknown: A Memoir