New York City police officer Graziano stands guard at a checkpoint on the corner of Nassau and Liberty in the financial district of Manhattan Tuesday morning, Sept. 18, 2001, a week after the terrorist attack on the World Trade Center. Visible on barrier is the front page of the New York Post with a photograph of Osama bin Ladin and the headline reading: "Wanted Dead or Alive." Large American flag in background adorns the front of the New York Stock Exchange. (AP Photo/Roberto Borea)
Police Officers & Civilians Flee Falling Towers
Police officers and civilians run away from New York's World Trade Center after an additional explosion rocked the buildings Tuesday morning, Sept. 11, 2001. In unprecedented show of terrorist horror, the 110-story World Trade Center towers collapsed in a shower of rubble and dust Tuesday morning after two hijacked airliners carrying scores of passengers slammed into the sides of the twin symbols of American capitalism. (AP Photo/Louis Lanzano)
U.S. Coast Guard
A U.S. Coast Guard cutter Tahoma stands guard offshore in New York harbor as smoke rises from the site of the terrorist attack on the Wolrld Trade Center in New York Friday, Sept. 14, 2001. (AP Photo/Roberto Borea)
The Statue of Liberty
The Statue of Liberty can be seen at first light from a view from Jersey City, N.J., as the lower Manhattan skyline is seen though a thick smoke filled the sky early Saturday, Sept. 15, 2001. New York continues to recover following terrorist attacks at the World Trade Center. (AP Photo/Dan Loh)
Police & National Guardsman Check Indentifications
Police and National Guardsman check indentifications at a checkpoint in New York's financial district Monday, Sept. 17, 2001. The financial district re-opened for the first time since the terrorist attack destroyed the World Trade Center. (AP Photo/Lawrence Jackson)
Word Trade Center Site
A New York police cruiser passes through a gate on Broadway, toward the scene of the collapsed World Trade Center in New York Monday, Sept. 24, 2001 as workers continue to sift through the debris for evidence and remains. (AP Photo/Elise Amendola)
Children's Letters are Handed Out
Tina Brookes, center, hands out copies of children's letters to New York City police officers Friday, Sept. 28, 2001, near the site of the World Trade Center attacks in New York. Brookes, a school counselor from Connelly Springs, N.C., is part of a group of volunteers from the Rev. Billy Grahams prayer network. (AP Photo/Beth A. Keiser)
Memorial Service
Canton (Mass.) Firefighter Paul Close, right, salutes as a procession passes under a large American flag during a memorial service for firefighter Gerard P. Dewan, in Boston, Saturday, Oct. 27, 2001. Some 3,000 firefighters attended the service for Dewan, a Boston native who died while responding with New York Fire Department's Ladder 3 to the World Trade Center on Sept. 11. (AP Photo/Angela Rowlings)
Smoke Fumes
Smoke fumes from the burning twin towers of the World Trade Center after hijacked planes crashed into them on Sept. 11, 2001 in New York City.(AP Photo/Richard Drew)
The Collapsed Towers
Destroyed mullions, the vertical struts which once faced the soaring outer walls of the World Trade Center towers, are the only thing left standing behind a lone fireman, after a terrorist attack on the twin towers of lower Manhattan Tuesday, Sept. 11, 2001. In an unprecedented show of terrorist horror, the 110-story towers collapsed in a shower of rubble and dust after two hijacked airliners carrying scores of passengers slammed into the sides of the twin symbols of American capitalism. (AP Photo/Mark Lennihan)
Emergency Workers Move Through Debris
Emergency workers move through the debris from the collapse of the World Trade Center in New York Tuesday, Sept. 11, 2001. Terrorists crashed two jetliners into the twin towers collapsing them and covering lower Manhattan with debris from the destruction. (AP Photo/Boudicon One)
The Second Tower Is Hit
Smoke billows from one of the towers of the World Trade Center and flames as debris explodes from the second tower, in this Sept. 11, 2001, file photo. In one of the most horrifying attacks ever against the U.S., terrorists crashed two airliners into the World Trade Center in a deadly series of blows that brought down the twin 110-story towers. (AP Photo/Chao Soi Cheong/FILE)
The Pentagon Crash Scene
Three unidentified rescue workers walk away from the crash site at the Pentagon in Arlington, Va., in this Sept. 11, 2001, file photo. In the most devastating terrorist onslaught ever waged against the United States, hijackers crashed two airliners into the World Trade Center, toppling its twin 110-story towers. The deadly calamity was witnessed on televisions across the world as another plane slammed into the Pentagon, and a fourth crashed outside Pittsburgh. (AP Photo/The Daily Progress, Dan Lopez/FILE)
What's Important Now
What's Important Now (WIN)? One, being ready and never being complacent. New York City police officers stand guard outside ground zero in New York, Saturday, Sept. 10, 2011. The National September 11 Memorial will be dedicated on the 10th anniversary of the attacks, Sept. 11, 2011, and will be open to the public the following day. (AP Photo/Oded Balilty)