WORLD TRADE CENTER
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 United States, terrorists crashed two airliners into the World Trade Center in a deadly series of blows that brought down the twin 110-story towers. This year will mark the fifth anniversary of the attacks. (AP Photo/Chao Soi Cheong/FILE)Photo by: AP
September 11th Terrorist Attacks
FIremen walk through a dust and debris covered street in lower Manhattan Tuesday, Sept. 11, 2001, after a terrorist attack at the World Trade Center. Two jet planes were crashed into the twin towers, collapsing them and covering the area with the debris.(AP Photo/Richard Cohen)Photo by: AP
WORLD TRADE CENTERS
Deputy U.S. marshal Dominic Guadagnoli helps a women after she was injured in the terrorist attack on the World Trade Center in New York, Tuesday, Sept. 11, 2001. (AP Photo/Gulnara Samoilova)Photo by: AP
September 11th Terrorist Attacks
The south tower collapses as smoke billows from both towers of the World Trade Center, in New York, Tuesday, Sept. 11, 2001. In one of the most horrifying attacks ever against the United States, 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/Jim Collins) Photo by: AP
WORLD TRADE CENTER
Smoke pours from one of the towers of the World Trade Center Tuesday, September 11, 2001, after terrorists crashed a plane into the building. Minutes later a second plane was crashed into the second tower. (AP Photo/Chao Soi Cheong)Photo by: AP
SEPT 11 2001 PENTAGON
Damage to the outer ring of the Pentagon is shown Tuesday, Sept. 11, 2001, after a hijacked airliner crashed into the building. (AP Photo/Steve Helber)Photo by: AP
TRADE CENTER
People make their way amid debris near the World Trade Center in New York Tuesday Sept. 11, 2001. In one of the most horrifying attacks ever against the United States, 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/Gulnara Samoilova)Photo by: AP
TRADE CENTER
Smoke billows from the twin towers of the World Trade Center in New York Tuesday Sept. 11, 2001. In one of the most horrifying attacks ever against the United States, 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/Gulnara Samoilova) Photo by: AP
September 11th Terrorist Attacks
Thick smoke billows into the sky from the area behind the Statue of Liberty, lower left, where the World Trade Center towers stood, on Tuesday, Sept. 11, 2001. The towers collapsed after terroists crashed two planes into them. (AP Photo/Daniel Hulshizer)Photo by: AP
September 11th Terrorist Attacks
The south tower of New York's World Trade Center collapses Tuesday Sept. 11, 2001. In one of the most horrifying attacks ever against the United States, 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/Richard Drew)Photo by: AP
September 11th Terrorist Attacks
The south tower of the World Trade Center begins to collapse following the terrorist attack on the New York landmark Tuesday, Sept. 11, 2001. The Millenium Hilton hotel is in foreground. (AP Photo/Amy Sancetta)Photo by: AP
September 11th Terrorist Attacks
With the skeleton of the World Trade Center twin towers in the background, New York City firefighters work amid debris on Cortlandt St. after the terrorist attacks of Tuesday, Sept. 11, 2001. (AP Photo/Mark Lennihan) Photo by: AP
SEPT. 11 ANNIVERSARY
The north tower of New York's World Trade Center shows the impact left by a hijacked Boeing 767, American Airlines Flight 11, in this Sept. 11, 2001, file photo. A person is just visible, standing at the bottom of the gaping hole. This year will mark the fifth anniversary of the attacks. (AP Photo/Amy Sancetta/FILE)Photo by: AP
SEPT 11 TERRORIST ATTACKS NYC
A man coated with ash and debris from the collapse of the World Trade Center south tower collects himself near City Hall in lower Manhattan Sept. 11, 2001. (AP Photo/Amy Sancetta)Photo by: AP
Attacks World Trade Center
Medical and emergency workers, who are standing in front of the Millenium Hilton, look towards where the World Trade Center towers used to be, 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)Photo by: AP
Flight 93 Memorial
In this Sept. 16, 2001 file photo an American flag flies from a makeshift altar overlooking the ongoing investigation of the crash of United Airlines Flight 93 in Shanksville, Pa. The plane crashed after being hijacked in the Sept. 11 terrorist attacks. The government will begin taking land from seven property owners so that the Flight 93 memorial can be built in time for the 10th anniversary of the 2001 terrorist attacks, the National Park Service said. (AP Photo/Gene J. Puskar, File)Photo by: AP
September 11th Terrorist Attacks
Rescue workers continue their efforts Monday, Sept. 24, 2001, at the site of the Sept. 11 World Trade Center terrorist attack in New York. (AP Photo/Ted S. Warren)Photo by: AP
September 11th Terrorist Attacks
The south tower begins to collapse as smoke billows from both towers of the World Trade Center, in New York, in this Sept. 11, 2001, file photo. In one of the most horrifying attacks ever against the United States, 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/Jim Collins/FILE)Photo by: AP
AP Images Best of the Decade
People in front of New York's St. Patrick's Cathedral react with horror as they look down Fifth Ave towards the World Trade Center towers after planes crashed into their upper floors in this Sept. 11, 2001, file photo. Explosions and fires collapsed the 110-story buildings. This year will mark the fifth anniversary of the attacks. (AP Photo/Marty Lederhandler/FILE)Photo by: AP
Attacks World Trade Center
The north tower of the World Trade Center collapses on September 11, 2001 in New York City. (AP Photo/Diane Bondareff)Photo by: AP
Attacks World Trade Center
An American flag at ground zero on the evening of Sept. 11, 2001 after the September 11 terrorist attacks on the World Trade Center in New York City.(AP Photo/Mark Lennihan)Photo by: AP
Attacks World Trade Center
The south tower of the World Trade Center twin towers begins to collapse after hijacked planes crashed into the towers on September 11, 2001 in New York City.(AP Photo/Richard Drew)Photo by: AP
Attacks World Trade Center
Firemen rinse debris off using a hose after the collapse of the twin towers of the World Trade Center on September 11, 2001 in New York City.(AP Photo/Richard Drew)Photo by: AP
Attacks World Trade Center
Debris fall from one of the burning twin towers of the World Trade Center after a hijacked plane crashed into the tower on September 11, 2001 in New York City.(AP Photo/Richard Drew)Photo by: AP
Terrorist Attacks
The twin towers of the World Trade Center burn behind the Empire State Building in New York, Sept. 11, 2001. In a horrific sequence of destruction, terrorists crashed two planes into the World Trade Center causing the twin 110-story towers to collapse. (AP Photo/Marty Lederhandler)Photo by: AP
9-11 Remains
In this Sept. 11, 2001 file photo, a helicopter flies over the Pentagon in Washington as smoke billows over the building. Partial remains of several 9/11 victims were incinerated by a military contractor and sent to a landfill, a government report said Tuesday, Feb. 28, 2012, in the latest of a series of revelations about the Pentagon's main mortuary for the war dead. The terrorist-hijacked airliner that slammed into the west side of the Pentagon killed 184 people. (AP Photo/Heesoon Yim, File)Photo by: AP
Attacks World Trade Center
A man jumps from the north tower of New York's World Trade Center Tuesday, Sept. 11, 2001 after terrorists crashed two hijacked airliners into the World Trade Center. (AP Photo/Richard Drew)Photo by: AP
Attacks World Trade Center
People run from the collapse of one of the twin towers of New York's World Trade Center in this Sept. 11, 2001, file photo. (AP Photo/FILE/Suzanne Plunkett) Photo by: AP
Attacks World Trade Center
Debris fall from one of the burning twin towers of the World Trade Center after a hijacked plane crashed into the tower on September 11, 2001 in New York City.(AP Photo/Richard Drew)Photo by: AP
September 11th Terrorist Attacks
People flee the falling South Tower of the World Trade Center on Tuesday, September 11, 2001. (AP Photo/Amy Sancetta)Photo by: AP
September 11th Terrorist Attacks
A lone firefighter moves through piles of debris at the site of the World Trade Center in New York, Tuesday, Sept. 11, 2001. Two Planes crashed into the upper floors of the World Trade Center towers minutes apart Tuesday morning, collapsing both 110-story buildings. (AP Photo/Graham Morrison)Photo by: AP
September 11th Terrorist Attacks
An American flag hangs from a light pole in front of shattered windows of a building in the World Trade Center complex Tuesday, Sept. 18, 2001 in New York. The World Trade Center twin towers were destroyed in a terrorist attack Sept. 11. (AP Photo/Mark Lennihan)Photo by: AP
September 11 NYC Aftermath
A woman looks at missing person posters of victims of the September 11 terrorist attacks on the World Trade Center in New York City on Sept. 14, 2001.(AP Photo/Robert Spencer)Photo by: AP
September 11 NYC Aftermath
A man lights a candle on Sept. 14, 2001 in memoriam of the victims of the September 11th terrorist attacks in New York City. (AP Photo/Robert F. Bukaty)Photo by: AP
CUSHMAN O'NEIL
Jessica Cushman, foreground left, and her best friend Melissa O'Neil, behind Cushman at right, join others Friday, Sept. 14, 2001, outside St. Agatha Parish Family Church in Los Angeles for a candlelight vigil honoring the victims of Tuesday's terrorist attacks. The vigil was part of the national day of prayer activities planned nationwide. (AP Photo/Ric Francis)Photo by: AP