The failures in intelligence-sharing were attributed to 1995 Justice Department policies limiting intelligence sharing , combined with CIA and NSA reluctance in revealing " sensitive sources and methods " such as tapped phones . Testifying before the 9/11 Commission in April 2004 , then-Attorney General John Ashcroft recalled that the " single greatest structural cause for the September 11th problem was the wall that segregated or separated criminal investigators and intelligence agents . " Clarke also wrote that " There were failures in the organizations ... failures to get information to the right place at the right time . " Early on the morning of September 11 , 2001 , 19 hijackers took control of four commercial airliners ( two Boeing 757s and two Boeing 767s ) en route to California ( three headed to LAX in Los Angeles and one to SFO in San Francisco ) after takeoffs from Logan International Airport in Boston , Massachusetts ; Newark Liberty International Airport in Newark , New Jersey ; and Washington Dulles International Airport in Loudoun and Fairfax counties in Virginia . Large planes with long flights were selected for hijacking because they would be full of fuel . The four flights were : Media coverage was extensive during the attacks and aftermath , beginning moments after the first crash into the World Trade Center . At 8:46 am , five hijackers crashed American Airlines Flight 11 into the northern façade of the World Trade Center 's North Tower ( 1 WTC ) . At 9:03 am , another five hijackers crashed United Airlines Flight 175 into the southern façade of the South Tower ( 2 WTC ) . Five hijackers flew American Airlines Flight 77 into the Pentagon at 9:37 am . A fourth flight , United Airlines Flight 93 , crashed near Shanksville , Pennsylvania , southeast of Pittsburgh , at 10:03 a.m. after the passengers fought the four hijackers . Flight 93 's target is believed to have been either the Capitol or the White House . Flight 93 's cockpit voice recorder revealed crew and passengers tried to seize control of the plane from the hijackers after learning through phone calls that Flights 11 , 77 , and 175 had been crashed into buildings that morning . Once it became evident that the passengers might gain control , the hijackers rolled the plane and intentionally crashed it
American Airlines Flight 11
American Airlines Flight 11
September 11 attacks