Defense Intelligence Agency (DIA) employees at the Pentagon take action in response to the terrorist attacks in New York, but they stay in their offices rather than evacuating and so a number of them will be killed when the Pentagon is hit. Sometime after the first hijacked plane crashed into the World Trade Center, at 8:46 a.m. (see 8:46 a.m. September 11, 2001), DIA analysts who are “[t]rained for this kind of emergency,” according to journalists Eric Schmitt and Thom Shanker, promptly respond to the incident. One group of them starts assessing what has happened; another group starts looking through classified intelligence reports in search of clues about how the attack was planned and conducted; and another group contacts colleagues at the CIA and other intelligence agencies to share information. [Schmitt and Shanker, 2011, pp. 18-19; Defense Intelligence Agency, 9/11/2015] After the second hijacked plane hits the WTC, at 9:03 a.m. (see 9:03 a.m. September 11, 2001), DIA personnel at the Pentagon “swung into crisis management,” Randall Blake, the DIA’s current intelligence terrorism chief, will later recall. Blake is called by his office chief at DIA headquarters at Bolling Air Force Base in Washington, DC. The two men discuss the situation and Blake’s office chief dispatches five or six people to the Pentagon. After reports start coming in stating that the first plane to hit the WTC was hijacked, Blake is summoned to a meeting with Rear Admiral Lowell Jacoby, the director of intelligence for the Joint Staff. At the meeting, Jacoby issues a set of concise instructions on how the unfolding crisis will be dealt with. [Blake, 2012, pp. 2 
] Apparently, no attempt is made to evacuate DIA employees from the Pentagon before the building is attacked. When Flight 77 hits it at 9:37 a.m., the plane will crash through the DIA’s Office of the Comptroller on the first floor of the building’s C Ring, killing seven employees there (see 9:37 a.m. September 11, 2001). [Washington Post, 3/11/2002; Defense Intelligence Agency, 9/11/2015]
5:40 p.m. September 11, 2001: Chairman of the Joint Chiefs Shelton Arrives at Pentagon Command Center after Returning to US
General Henry Shelton, the chairman of the Joint Chiefs of Staff, finally arrives at the National Military Command Center (NMCC) at the Pentagon after returning to the US when his flight to Europe was aborted.
Vice Chairman Updates Shelton – After Shelton enters the NMCC, General Richard Myers, the vice chairman of the Joint Chiefs of Staff, briefs him. Myers says that Air National Guard and regular Air Force combat air patrols are flying above major US cities under AWACS control, the entire US military is on Threatcon level Delta, and the Joint Forces Command is sending headquarters units to New York and Washington, DC.
Intelligence Director Says Only One ‘Hint’ Indicated Possible Attack – Shelton then turns to Vice Admiral Tom Wilson, the director of the Defense Intelligence Agency, and Rear Admiral Lowell Jacoby, the director of intelligence for the Joint Staff, and asks them, “Have we had any intel ‘squeaks’ on an attack like this—anything at all?” Wilson replies: “The only possible hint of this coming was several months ago when we got a single intercept requesting jumbo jet training. Since then, there’s been nothing.” Myers will later comment that Wilson is “referring to the vast electronic signals data-mining operations of our intelligence community that targeted known terrorist networks, such as al-Qaeda and their allies.” [Myers and McConnell, 2009, pp. 159]
Shelton Flying to Europe at Time of Attacks – Shelton was flying across the Atlantic Ocean to Hungary for a NATO conference when he learned of the terrorist attacks in the US, and had ordered that his plane return to Washington (see (8:50 a.m.-10:00 a.m.) September 11, 2001). However, the plane was repeatedly denied permission to enter US airspace (see (After 9:45 a.m.) September 11, 2001) and only landed at Andrews Air Force Base, just outside Washington, at 4:40 p.m. (see 4:40 p.m. September 11, 2001). From there, three patrol cars and about a dozen motorcycle cops escorted the chairman and his accompanying staff members as they were driven to the Pentagon. Once at the Pentagon, Shelton initially went to his office and then visited the site of the attack, to see the wreckage there. After returning to the building, he headed to the NMCC. [Federal Aviation Administration, 9/11/2001 ; Giesemann, 2008, pp. 22-32; Shelton, Levinson, and McConnell, 2010, pp. 430-436; Air Force Magazine, 9/2011 ]
Chairman in Office for Much of Evening – Shelton will spend much of the evening in his office with staff, preparing for meetings of the National Security Council later this evening and the following day (see (9:00 p.m.-10:00 p.m.) September 11, 2001 and September 12, 2001). At 6:42 p.m., he will join Secretary of Defense Donald Rumsfeld and Senators Carl Levin (D-MI) and John Warner (R-VA) to give a news briefing (see 6:42 p.m. September 11, 2001), and at around 9:00 p.m. he will head to the White House for the National Security Council meeting there. [CNN, 9/12/2001; Priest, 2003, pp. 37; Shelton, Levinson, and McConnell, 2010, pp. 436]
