Photo Gallery: Sept. 11, 2001 NEW YORK, UNITED STATES - SEPTEMBER 11: (FRANCE OUT) Lower Manhattan and the World Trade Center after attack by terrorist hijacked airliners, which destroyed the Twin Towers and killed more than 3000 people in New York, United states on September 11, 2001(Photo by Alan CHIN/Gamma-Rapho via Getty Images)Photo by: Alan CHIN Photo Gallery: Sept. 11, 2001 394262 03: Smoke comes out from the west wing of the Pentagon building September 11, 2001 in Arlington, Va., after a plane crashed into the building and set off a huge explosion. (Photo by Alex Wong/Getty Images)Photo by: Alex Wong Photo Gallery: Sept. 11, 2001 394465 01: US President George W. Bush tours the World Trade Center disaster site aboard his helicopter Marine One September 14, 2001 with New York Mayor Rudolph Giuliani (L) and New York Governor George Pataki (R). (Photo by Eric Draper/White House/Getty Images)Photo by: The White House Photo Gallery: Sept. 11, 2001 394261 38: People evacuate the area around the World Trade Center after it was hit by two planes September 11, 2001 in New York City. (Photo by Mario Tama/Getty Images)Photo by: Mario Tama Photo Gallery: Sept. 11, 2001 NEW YORK - SEPTEMBER 11: The south tower of the World Trade Center collapses September 11, 2001 in New York City. (Photo by Thomas Nilsson/ Getty Images)Photo by: Thomas Nilsson Photo Gallery: Sept. 11, 2001 394261 50: Civilians flee as a tower of the World Trade Center collapses September 11, 2001 after two airplanes slammed into the twin towers in an alleged terrorist attack. (Photo by Mario Tama/Getty Images)Photo by: Mario Tama Photo Gallery: Sept. 11, 2001 394509 01: U.S. President George W. Bush speaks to Vice President Dick Cheney by phone aboard Air Force One September 11, 2001 after departing Offutt Air Force Base in Nebraska. (Photo by Eric Draper/The White House/Getty Images)Photo by: The White House Photo Gallery: Sept. 11, 2001 394263 15: (PUERTO RICO OUT) Policemen and firemen run away from the huge dust cloud caused as the World Trade Center's Tower One collapses after terrorists crashed two hijacked planes into the twin towers, September 11, 2001 in New York City. (Photo by Jose Jimenez/Primera Hora/Getty Images)Photo by: Jose Jimenez/Primera Hora Photo Gallery: Sept. 11, 2001 New York, UNITED STATES: TO GO WITH AFP STORY "Americans mark 9/11 anniversary with new questions on vulnerability" - (FILES) The rubble of the World Trade Center smoulders following a terrorist attack 11 September 2001 in New York. Americans mark the fourth anniversary of the September 11, 2001 terror attacks Sunday nagged by new burning questions about their readiness to confront a major disaster after the debacle of Hurricane Katrina. AFP PHOTO/Alex Fuchs (Photo credit should read ALEX FUCHS/AFP/Getty Images)Photo by: ALEX FUCHS Photo Gallery: Sept. 11, 2001 ARLINGTON, VA - SEPTEMBER 14, 2001: (SEPTEMBER 11 RETROSPECTIVE) A military helicopter flies in front of the Pentagon September 14, 2001 in Arlington, Virginia at the impact site where a hijacked airliner crashed into the building. (Photo by Stephen J. Boitano/Getty Images)Photo by: Stephen J. Boitano Photo Gallery: Sept. 11, 2001 NEW YORK, UNITED STATES: US-ATTACKS-3RD ANNIVERSARY (FILES) This 11 September 2001 file photo shows a man standing amid rubble, calling out asking if anyone needs help, following the collapse of the first World Trade Center tower in New York after two hijacked planes crashed into the buildings. 11 September, 2004 marks the third anniversary of the terrorist attacks responsible for the deaths of nearly three thousand people. AFP PHOTO/FILES/Doug KANTER (Photo credit should read DOUG KANTER/AFP/Getty Images)Photo by: DOUG KANTER Photo Gallery: Sept. 11, 2001 NEW YORK - SEPTEMBER 11, 2001: (SEPTEMBER 11 RETROSPECTIVE) Smoke pours from the twin towers of the World Trade Center after they were hit by two hijacked airliners in a terrorist attack September 11, 2001 in New York City. (Photo by Robert Giroux/Getty Images)Photo by: Robert Giroux Photo Gallery: Sept. 11, 2001 NEW YORK - SEPTEMBER 11: An unidentified New York City firefighter walks away from Ground Zero after the collapse of the Twin Towers September 11, 2001 in New York City. The World Trade Center's Twin Towers and the Pentagon were attacked by terrorists using commercial airliners as missiles. (Photo by Anthony Correia/Getty Images)Photo by: Anthony Correia Photo Gallery: Sept. 11, 2001 394558 06: A New York City fireman calls for 10 more rescue workers to make their way into the rubble of the World Trade Center September 14, 2001 days after the September 11, 2001 terrorist attack. (U.S. Navy Photo by Jim Watson/Getty Images)Photo by: U.S. Navy Photo Gallery: Sept. 11, 2001 394276 05: The Washington Momument stands in the background as firefighters pour water on a fire at the Pentagon that was caused by a hijacked plane crashing into the building September 11, 2001 in Washington, DC. (Photo by Greg Whitesell/Getty Images)Photo by: Greg Whitesell Photo Gallery: Sept. 11, 2001 394261 111: People walk in the street in the area where the World Trade Center buildings collapsed September 11, 2001 after two airplanes slammed into the twin towers in a suspected terrorist attack. (Photo by Mario Tama/Getty Images)Photo by: Mario Tama Photo Gallery: Sept. 11, 2001 NEW YORK, UNITED STATES: US President George W. Bush (L) speaks through a megaphone beside retired firefighter Bob Beckwith, 69, to firemen and other workers 14 September 2001 at the site of the destroyed World Trade Center. AFP PHOTO/Paul J. RICHARDS (Photo credit should read PAUL J. RICHARDS/AFP/Getty Images)Photo by: PAUL J. RICHARDS Photo Gallery: Sept. 11, 2001 394262 02: Smoke comes out from the west wing of the Pentagon building September 11, 2001 in Arlington, Va., after a plane crashed into the building and set off a huge explosion. (Photo by Alex Wong/Getty Images)Photo by: Alex Wong Photo Gallery: Sept. 11, 2001 SARASOTA, UNITED STATES: (FILES): This 11 September 2001 file photo from an early morning school reading event Sarasota, Florida, shows White house Chief of Staff Andrew Card (L) informing US President George W. Bush (R) of the attacks on the World Trade Center in New York. A bipartisan US commission pins the blame for the 11 September 2001 terror attacks on a broad array of lapses by federal and local law enforcement officials and intelligence agencies, in its final report to be released 22 July 2004. AFP PHOTO/FILES/Paul J. RICHARDS (Photo credit should read PAUL J. RICHARDS/AFP/Getty Images)Photo by: PAUL J. RICHARDS