Donald Rumsfeld
The United States was attacked on September 11, 2001 by al Qaeda terrorists who hijacked commercial airliners and crashed them in coordinated strikes into both towers of the World Trade Center in Lower Manhattan, New York City and the Pentagon in Washington, D.C. The fourth plane crashed into a field in Shanksville, Pennsylvania, and its target was likely a prominent building in Washington, D.C., most probably either the Capitol Building or the White House. Within three hours of the start of the first hijacking and two hours after American Airlines Flight 11 struck the World Trade Center, Rumsfeld raised the defense condition signaling of the United States offensive readiness to DEFCON 3, the highest it had been since the Arab-Israeli war in 1973.
Kroll Inc.
Kroll were responsible for revamping security at the World Trade Center after the 1993 World Trade Center bombing. They also took on responsibility for security at Chicago's Sears Tower following the September 11, 2001 attacks.
Just prior to the September 11 attacks, Kroll Inc., with the guidance of Jerome Hauer, at the time the Managing director of their Crisis and Consulting Management Group,
hired former FBI special investigator John P. O'Neill, who specialized in the Al-Qaeda network held responsible for the 1993 bombing, to head the security at the WTC complex. O'Neill died in the attacks.