11 Years After Sept. 11

Joe Biden, Ken Salazar Vice President Joe Biden, left, and Interior Secretary Ken Salazar arrive at the Flight 93 National Memorial in Shanksville, Pa., for a memorial service, Tuesday, Sept. 11, 2012. (AP Photo/Gene J. Puskar)

AP Photo/Gene J. Puskar

Sept 11 Anniversary New York City Police Dept. bugler Gabe Perdomo warms up while standing next to the South Pool of the World Trade Center Memorial, during the 11th anniversary ceremonies, in New York, Tuesday, Sept. 11, 2012. (AP Photo/Justin Lane, Pool, EPA)

AP Photo/Justin Lane, Pool, EPA

Sept 11 Anniversary Police officers of the Port Authority of New York and New Jersey, carry an American flag that flew over the World Trade Center towers, during the 11th anniversary ceremonies at the site of the World Trade Center,Tuesday, Sept. 11, 2012, in New York. (AP Photo/Justin Lane, Pool, EPA)

AP Photo/Justin Lane, Pool, EPA

Sept 11 Anniversary Police officers of the Port Authority of New York and New Jersey, carry an American flag that flew over at the World Trade Center towers, during the 11th anniversary ceremonies at the site of the World Trade Center, in New York, Tuesday Sept. 11, 2012. (AP Photo/Justin Lane, Pool, EPA)

AP Photo/Justin Lane, Pool, EPA

Sept 11 Anniversary New York City firefighter Dan Kenny looks out over the South Pool of the World Trade Center Memorial, during the 11th anniversary ceremonies at the site of the World Trade Center, Tuesday, Sept. 11, 2012. (AP Photo/Justin Lane. Pool, EPA)

AP Photo/Justin Lane. Pool, EPA

Sept 11 Anniversary Police Officers, of the Port Authority of New York and New Jersey, carry an American flag that flew over at the World Trade Center towers, during anniversary ceremonies at the site of the World Trade Center, in New York,Tuesday Sept. 11, 2012. (AP Photo/Justin Lane, Pool, EPA)

AP Photo/Justin Lane, Pool, EPA

Sept 11 Anniversary Maria Rodriguez sits with photos of her son-in-law Emilio Ortiz as friends and relatives of the victims of the Sept. 11 terrorist attacks on the World Trade Center gather for a ceremony marking the 11th anniversary of the attacks at the National September 11 Memorial in New York, Tuesday, Sept. 11, 2012. (AP Photo/Jason DeCrow)

AP Photo/Jason DeCrow

Sept 11 Anniversary Friends and relatives of the victims of the Sept. 11 terrorist attacks on the World Trade Center gather for a ceremony marking the 11th anniversary of the attacks at the National September 11 Memorial at the World Trade Center site in New York, Tuesday, Sept. 11, 2012. (AP Photo/Jason DeCrow)

AP Photo/Jason DeCrow

Sept 11 Anniversary Alicia Watkins, of Washington, DC, makes a rubbing of a friend's name at the South Pool of the World Trade Center Memorial during the 11th anniversary observance at the site in New York, Tuesday Sept. 11, 2012. (AP Photo/Justin Lane, EPA, Pool)

AP Photo/Justin Lane, EPA, Pool

Sept 11 Anniversary A firefighter makes a rubbing of a victim's name as friends and relatives of the victims of the Sept. 11 terrorist attacks on the World Trade Center gather for a ceremony marking the 11th anniversary of the attacks at the National September 11 Memorial in New York, Tuesday, Sept. 11, 2012. (AP Photo/Jason DeCrow)

AP Photo/Jason DeCrow

Sept 11 Anniversary Linda Torrens holds a portrait of her cousin Janine Nicole Gonzalez during the observances held on the eleventh anniversary of the attacks on the World Trade Center, Tuesday, Sept. 11, 2012 in New York. (AP Photo/Mary Altaffer, Pool)

AP Photo/Mary Altaffer, Pool

Barack Obama, Michelle Obama President Barack Obama first lady Michelle Obama, and members of the White House staff pause during a moment of silence to mark the 11th anniversary of the Sept, 11th, Tuesday, Sept. 11, 2012, on the South Lawn of the White House in Washington. (AP Photo/Carolyn Kaster)

AP Photo/Carolyn Kaster

Barack Obama, Michelle Obama President Barack Obama, accompanied by first lady Michelle Obama, place Challenge Coins on graves in Section 60 at Arlington National Cemetery in Arlington, Va. , Tuesday, Sept. 11, 2012, to mark the 11th anniversary of the 9/11 attacks. (AP Photo/Carolyn Kaster)

AP Photo/Carolyn Kaster

Khudeza Begum Khudeza Begum etches the name of her slain nephew during ceremonies marking the eleventh anniversary of the terrorist attacks at the World Trade Center, Tuesday, on Sept. 11, 2012 in New York. Begum, who is from Bangladesh, lost her nephew Nural Miah and his wife Shakila Yasmin, in the Sept.11, 2001 attacks. (AP Photo/John, Pool)

AP Photo/John, Pool

Sept 11 Anniversary Marshall Rodriguez, from New York, holds an American flag at the edge of the south reflecting pool of the World Trade Center Memorial while visiting the names of friends he lost in the Sept . 11 attacks, during the 11th anniversary observance at the site, in New York, Tuesday Sept. 11, 2012. AP Photo/Justin Lane, Pool)

Sept 11 Anniversary Mourners pause near American flags adorning a wall at the National September 11 Memorial during the observance of the 11th anniversary of September 11 in New York on Tuesday, Sept. 11, 2012. (AP Photo/Chang W. Lee, New York Times, Pool)

AP Photo/Chang W. Lee, New York Times, Pool

Michelle Mudge U.S. Army 2ND Lt. Michelle Mudge wipes a tear during ceremonies marking the eleventh anniversary of the terrorist attacks at the World Trade Center, Tuesday, Sept. 11, 2012 in New York. (AP Photo John Moore, Pool)

AP Photo John Moore, Pool

Barack Obama Audience watch and some wipe tears as President Barack Obama speaks at the Pentagon Memorial, Tuesday, Sept. 11, 2012, during a ceremony to mark the 11th anniversary of the 9/11 attacks. (AP Photo/Carolyn Kaster)

AP Photo/Carolyn Kaster

Sept 11 Anniversary Judy Parisio places an American flag in one of the engraved names that borders the north reflecting pool of the World Trade Center Memorial, during the ceremonies marking the 11th anniversary of the Sept. 11 attacks, in New York, Tuesday Sept. 11, 2012. (AP Photo/Mike Segar, Pool)

AP Photo/Mike Segar, Pool

Sept 11 Anniversary Two men bow their heads as friends and relatives of the victims of the Sept. 11 terrorist attacks on the World Trade Center attend a ceremony marking the 11th anniversary of the attacks at the National September 11 Memorial at the World Trade Center site in New York, Tuesday, Sept. 11, 2012. (AP Photo/Jason DeCrow)

AP Photo/Jason DeCrow

Sept 11 Anniversary A man embraces a woman as friends and relatives of the victims of the Sept. 11 terrorist attacks on the World Trade Center attend a ceremony marking the 11th anniversary of the attacks at the National September 11 Memorial at the World Trade Center site in New York, Tuesday, Sept. 11, 2012. (AP Photo/Jason DeCrow)

AP Photo/Jason DeCrow

Sept 11 Anniversary One World Trade Center, center, rises above the National September 11 Memorial and Museum at the World Trade Center, Thursday, Sept. 6, 2012 in New York. Tuesday will mark the eleventh anniversary of the terrorist attacks of Sept. 11, 2001. (AP Photo/Mark Lennihan)

Sept 11 Museum Exhibition Photos of victims of the attacks of September 11 and messages from their loved ones, are shown at a news conference, Monday, Sept. 10, 2012 in New York. On the eve of the Sept. 11 anniversary, the faces and recorded voices of those who died have been unveiled as part of the future 9/11 Memorial Museum. (AP Photo/Mark Lennihan)

AP Photo/Mark Lennihan

Sept 11 Anniversary One World Trade Center, is now up to 104 floors, rises above the lower Manhattan skyline, Thursday, Sept. 6, 2012 in New York. Tuesday will mark the eleventh anniversary of the terrorist attacks of Sept. 11, 2001. (AP Photo/Mark Lennihan)

AP Photo/Mark Lennihan

Sept 11 Anniversary Passing clouds are reflected in One World Trade Center, now up to 104 floors, Thursday, Sept. 6, 2012 in New York. Tuesday will mark the eleventh anniversary of the terrorist attacks of Sept. 11, 2001. (AP Photo/Mark Lennihan)

AP Photo/Mark Lennihan

Sept 11 Health FILE - In this Oct. 11, 2001 file photo, firefighters make their way over the ruins and through clouds of smoke at the World Trade Center in New York. Many of the first responders and those who labored at the site in the months following the attacks suffer from a variety of respiratory ailments after working at the World Trade Center site. Nearly two years after President Obama signed the James Zadroga 9/11 Health and Compensation Act into law, about 60,000 responders and survivors continue to receive monitoring and treatment for their illnesses as part of the World Trade Center Health Program, one of the law’s two components. (AP Photo/Stan Honda, Pool, File

APTOPIX Sept 11 Anniversary One World Trade Center, center, rises above the National September 11 Memorial and Museum at the World Trade Center, Thursday, Sept. 6, 2012 in New York. Tuesday will mark the eleventh anniversary of the terrorist attacks of Sept. 11, 2001. The World Financial Center is on the left, and Four World Trade Center is at right. (AP Photo/Mark Lennihan)

AP Photo/Mark Lennihan

Sept 11 Construction Glance FILE - In this file photo of June 23, 2012, construction cranes perch on top of One World Trade Center, left, and Four World Trade Center in New York. Eleven years after terrorists attacked the World Trade Center, the new World Trade Center now dominates the lower Manhattan skyline. (AP Photo/Mark Lennihan, File)

AP Photo/Mark Lennihan, File

Sept 11 Anniversary One World Trade Center, left, and Four World Trade Center, right, rise above the National September 11 Memorial and Museum at the World Trade Center, Thursday, Sept. 6, 2012 in New York. Tuesday will mark the eleventh anniversary of the terrorist attacks of Sept. 11, 2001. (AP Photo/Mark Lennihan)

AP Photo/Mark Lennihan

Sept 11 Tribute in Light The Tribute in Light shines above the World Trade Center and the Statue of Liberty, left, Monday, Sept. 10, 2012, as seen from Bayonne, N.J. Tuesday will mark the eleventh anniversary of the terrorist attacks of Sept. 11, 2001. The tallest tower is 1 World Trade Center, now up to 105 floors. In the center is 4 World Trade Center. (AP Photo/Mark Lennihan)

AP Photo/Mark Lennihan

Sept 11 Tribute in Light The Tribute in Light shines above the World Trade Center in New York and the Statue of Liberty, left, Monday, Sept. 10, 2012 in this photo taken from Bayonne, N.J. Tuesday will mark the eleventh anniversary of the terrorist attacks of Sept. 11, 2001. The tallest tower is 1 World Trade Center, now up to 105 floors. In the center is 4 World Trade Center. (AP Photo/Mark Lennihan)

AP Photo/Mark Lennihan

APTOPIX Sept 11 Anniversary Visitors to the National September 11 Memorial walk below the rising towers 1 World Trade Center, left, and 4 World Trade Center, Monday, Sept. 10, 2012 in New York. Tuesday will mark the eleventh anniversary of the attacks of Sept. 11, 2001. (AP Photo/Mark Lennihan)

AP Photo/Mark Lennihan

Sept 11 Anniversary A woman holds a young boy as friends and relatives of the victims of the Sept. 11 terrorist attacks on the World Trade Center attend a ceremony marking the 11th anniversary of the attacks at the National September 11 Memorial at the World Trade Center site in New York, Tuesday, Sept. 11, 2012. (AP Photo/Jason DeCrow)

AP Photo/Jason DeCrow

Sept 11 Anniversary One World Trade Center, center, rises above the National September 11 Memorial and Museum at the World Trade Center, Thursday, Sept. 6, 2012 in New York. Tuesday will mark the eleventh anniversary of the terrorist attacks of Sept. 11, 2001. (AP Photo/Mark Lennihan)

AP Photo/Mark Lennihan

Sept 11 Pennsylvania Visitors to the Flight 93 National Memorial in Shanksville, Pa., participate in a sunset memorial service on Monday, Sept. 10, 2012. Tuesday marks the 11th anniversary of the Sept. 11, 2001 terrorist attack. (AP Photo/Gene J. Puskar)

AP Photo/Gene J. Puskar

Sept 11 Anniversary A boy runs among flags flying at Pepperdine University in honor of the victims of the Sept. 11, 2001 attacks against the United States, Monday Sept. 10, 2012 in Malibu, Calif. Nearly 3,000 flags for of each person killed that day were erected. The installation of flags has been an annual event since September 2011 and will remain on display until the close of Pepperdine's 75th anniversary celebrations on Sept. 19. (AP Photo/David McNew)

AP Photo/David McNew

CORRECTION Sept 11 Anniversary Flags hang at Pepperdine University after sunset in honor of the victims of the Sept. 11, 2001 attacks against the United States, Monday Sept. 10, 2012 in Malibu, Calif. One flag from the nationality of each person killed that day was erected. The installation of flags has been an annual event since September 2011 and will remain on dispaly until the close of Pepperdine's 75th anniversary celebrations on September 19. (AP Photo/David McNew)

APTOPIX Sept 11 Anniversary A test of the Tribute in Light shines skyward over lower Manhattan, Friday, Sept. 7, 2012 in New York. The tribute will shine the night of Tuesday, Sept. 11 over New York, eleven years after the terrorist attacks. (AP Photo/Mark Lennihan)

AP Photo/Mark Lennihan

Sept 11-Georgia Some 2,977 American flags representing each person killed in the attacks of September 11 decorate a lawn as a passerby takes a photo on the campus of Georgia Tech Institute of Technology Monday, Sept. 10, 2012, in Atlanta. Tuesday will mark the eleventh anniversary of the attacks of Sept. 11, 2001. (AP Photo/David Goldman)

AP Photo/David Goldman

Afghanistan U.S. soldiers and NATO service members take a moment of silence to remember the victims of the terrorist attacks on Sept. 11, 2001, during a ceremony marking the 11th anniversary of the attacks, at NATO camp Kaia, Kabul, Afghanistan, Tuesday, Sept. 11, 2012. (AP Photo/Musadeq Sadeq)

AP Photo/Musadeq Sadeq

Afghanistan U.S. soldiers and NATO service members watch a slideshow showing the Sept. 11 attacks during a ceremony marking the 11th anniversary of the Sept. 11 attacks that killed almost 3,000 in the United States, at NATO camp Kaia in Kabul, Afghanistan, Tuesday, Sept. 11, 2012. (AP Photo/Musadeq Sadeq)

AP Photo/Musadeq Sadeq

Sept 11 Anniversary People walk near the construction site of One World Trade Center during the 11th anniversary of the Sept. 11 terrorist attacks, Tuesday, Sept. 11, 2012, in New York. As in past years, thousands were expected to gather at the World Trade Center site in New York, the Pentagon and Shanksville, Pennsylvania, to read the names of nearly 3,000 victims killed in the worst terror attack in U.S. history. (AP Photo/Julio Cortez)

AP Photo/Julio Cortez

APTOPIX Sept 11 Anniversary A boy runs among flags flying at Pepperdine University in honor of the victims of the Sept. 11, 2001 attacks against the United States, Monday Sept. 10, 2012 in Malibu, Calif. Nearly 3,000 flags for of each person killed that day were erected. The installation of flags has been an annual event since September 2011 and will remain on display until the close of Pepperdine's 75th anniversary celebrations on Sept. 19. (AP Photo/David McNew)

AP Photo/David McNew

A person stops to read names in New Jersey's memorial to the 749 people from the state lost during the Sept. 11 terrorist attacks on the World Trade Center, as One World Trade Center, now up to 104 floors, looms in the distance across the Hudson River, Tuesday, Sept. 11, 2012 in Jersey City, N.J. Americans paused again Tuesday to mark the 11th anniversary of the Sept. 11, 2001, terror attacks with familiar ceremonies, but also a sense that it's time to move forward after a decade of remembrance. (AP Photo/Mel Evans)

AP Photo/Mel Evans

Barack Obama, Martin Dempsey, Leon Panetta President Barack Obama, flanked by Defense Defense Leon Panetta, left, and Joint Chiefs Chairman Gen. Martin Dempsey, place their hands over their hearts at the Pentagon Memorial,Tuesday, Sept. 11, 2012, during a ceremony to mark the 11th anniversary of the Sept. 11 attacks. (AP Photo/Carolyn Kaster)

AP Photo/Carolyn Kaster

Sept 11 Anniversary A New York City Police officer salutes a flag hanging from the One World Trade Center building, during ceremonies for the 11th anniversary of the attacks at the World Trade Center, in New York, Tuesday Sept. 11, 2012. (AP Photo/John Moore, Pool)

AP Photo/John Moore, Pool

Tampa Fire, World Trade Center beam, 9/11 Memorial. Members of the Tampa Fire Dept., stand at attention near a section of a steel beam from one of the the World Trade Center buildings Tuesday morning Sept. 11, 2012 at the Tampa Firefighters Museum in Tampa, Fla. Americans nationwide paused for a moment of silence to honor those who lost their lives on the 11th anniversary of the 2001 terrorist attacks. (AP Photo/Chris O'Meara)

AP Photo/Chris O'Meara

The construction of One World Trade Center, now up to 104 floors, is seen Tuesday, Sept. 11, 2012, across the Hudson River, as people stop to read names in New Jersey's memorial to the 749 people from the state lost during the Sept. 11 terrorist attacks on the World Trade Center. Americans paused again Tuesday to mark the 11th anniversary of the Sept. 11, 2001, terror attacks with familiar ceremonies, but also a sense that it's time to move forward after a decade of remembrance. (AP Photo/Mel Evans)

AP Photo/Mel Evans

Sept 11 Anniversary Shadows of mourners are cast on the memorial wall during the commemoration ceremony of the 11th anniversary of the Sept. 11, 2001 terrorist attacks by the North Pool at World Trade Center in New York on Tuesday, Sept. 11, 2012. (AP Photo/The New York Times, Chang W. Lee, Pool)

AP Photo/The New York Times, Chang W. Lee, Pool

Brooke Warren Brooke Warren looks back across the Hudson River as she walks her dogs at Liberty State Park Tuesday, Sept. 11, 2012, in Jersey City, N.J. Americans paused again Tuesday to mark the 11th anniversary of the Sept. 11, 2001, terror attacks with familiar ceremonies, but also a sense that it's time to move forward after a decade of remembrance. As in past years, thousands were expected to gather at the World Trade Center site in New York, the Pentagon and Shanksville, Pa., to read the names of nearly 3,000 victims killed in the worst terror attack in U.S. history. (AP Photo/Mel Evans)

AP Photo/Mel Evans

Sept 11 Anniversary American flags are placed in the engravings of people's names that border the reflecting pools of the World Trade Center Memorial, who died in the Sept. 11 World Trade Center attacks, during the 11th anniversary observance, in New York, Tuesday, Sept. 11, 2012. (AP Photo/Justin Lane, Pool)

AP Photo/Justin Lane, Pool

Sept 11 Anniversary A flower and an American flag are placed next to the names inscribed on the edge of one of the World Trade Center Memorial reflecting pools, during the observance held on the eleventh anniversary of the attacks on the World Trade Center, Tuesday, Sept. 11, 2012 in New York. (AP Photo/Mary Altaffer, Pool)

AP Photo/Mary Altaffer, Pool

Sept 11 Anniversary Sofia, Dominick, and Maureen Esposito, left to right, listen as the name of their relative Frankie Esposito is read during the observance of the eleventh anniversary of the attacks on the World Trade Center,Tuesday, Sept. 11, 2012 in New York. (AP Photo/Mary Altaffer, Pool)

AP Photo/Mary Altaffer, Pool

Sept 11 Anniversary Police officers of the Port Authority of New York and New Jersey carry an American flag that flew over at the World Trade Center towers, during the 11th anniversary ceremony at the site of the World Trade Center in New York, Tuesday, Sept. 11, 2012. (AP Photo/Justin Lane, Pool)

AP Photo/Justin Lane, Pool

Sept 11 Anniversary Friends and relatives of the victims of the Sept. 11 terrorist attacks on the World Trade Center attend a ceremony marking the 11th anniversary of the attacks at the National September 11 Memorial at the World Trade Center site in New York, Tuesday, Sept. 11, 2012. (AP Photo/Jason DeCrow)

AP Photo/Jason DeCrow

Sept 11 Anniversary Workers unfurl a flag hanging from the wall of One World Trade Center as friends and relatives of the victims of the Sept. 11 terrorist attacks on the World Trade Center attend a ceremony marking the 11th anniversary of the attacks at the National September 11 Memorial at the World Trade Center site in New York, Tuesday, Sept. 11, 2012. (AP Photo/Jason DeCrow)

AP Photo/Jason DeCrow

Sept 11 Anniversary A man gathers with friends and relatives of the victims of the Sept. 11 terrorist attacks on the World Trade Center at a ceremony marking the 11th anniversary of the attacks at the National September 11 Memorial at the World Trade Center site in New York, Tuesday, Sept. 11, 2012. (AP Photo/Jason DeCrow)

AP Photo/Jason DeCrow

Sept 11 Anniversary Friends and relatives of the victims of the Sept. 11 terrorist attacks on the World Trade Center attend a ceremony marking the 11th anniversary of the attacks at the National September 11 Memorial at the World Trade Center site in New York, Tuesday, Sept. 11, 2012.(AP Photo/Jason DeCrow)

AP Photo/Jason DeCrow

Sept 11 Anniversary The World Trade Center Flag is presented as friends and relatives of the victims of the Sept. 11 terrorist attacks on the World Trade Center attend a ceremony marking the 11th anniversary of the attacks at the National September 11 Memorial at the World Trade Center site in New York, Tuesday, Sept. 11, 2012. (AP Photo/Jason DeCrow)

AP Photo/Jason DeCrow

Marcio Rodriguez Marcio Rodriguez holds a United States flag as he pays respects in front of the construction site of One World Trade Center during the 11th anniversary of the Sept. 11 terrorist attacks, Tuesday, Sept. 11, 2012, in New York. (AP Photo/Julio Cortez)

AP Photo/Julio Cortez

Sept 11 Anniversary A New York City Police officer salutes a flag hanging from the One World Trade Center building, during ceremonies for the 11th anniversary of the attacks at the World Trade Center, in New York, Tuesday Sept. 11, 2012. (AP Photo/John Moore, Pool, Getty Images)

AP Photo/John Moore, Pool, Getty Images

Sept 11 Anniversary Police officers of the Port Authority of New York and New Jersey, carry an American flag that flew over the World Trade Center towers, during the 11th anniversary ceremonies at the site of the World Trade Center,Tuesday, Sept. 11, 2012, in New York. (AP Photo/Justin Lane, Pool, EPA)

AP Photo/Justin Lane, Pool, EPA

A service at the Prince William County Sept. 11 memorial began at 1:30 p.m. with a reading of the names of 19 county residents who died that day. (WTOP/Kathy Stewart)

WTOP/Kathy Stewart

Sept 11 Anniversary Ten lit candles and ten red roses rest on a memorial at New York City's Engine 8 and Ladder 2 firehouse on East 51st Street following a ceremony honoring fallen FDNY firefighters and victims on the 11th anniversary of the Sept. 11, 2001 terrorist attacks, Tuesday, Sept. 11, 2012 in New York. Ten members of the station died in the attack. (AP Photo/Charles Krupa)

AP Photo/Charles Krupa

Afghanistan Sept 11 US Attacks U.S. Marine Gen. John Allen, second left, the top commander of U.S. and coalition troops in Afghanistan, salutes during a ceremony marking the 11th anniversary of the Sept. 11 attacks, at the NATO headquarters in Kabul, Afghanistan, Tuesday, Sept. 11, 2012. (AP Photo/Ahmad Jamshid)

AP Photo/Ahmad Jamshid

Sept 11 Anniversary A boy observes a moment of silence as friends and relatives of the victims of the Sept. 11 terrorist attacks on the World Trade Center attend a ceremony marking the 11th anniversary of the attacks at the National September 11 Memorial at the World Trade Center site in New York, Tuesday, Sept. 11, 2012. (AP Photo/Jason DeCrow)

AP Photo/Jason DeCrow

Sept 11 Anniversary A woman becomes emotional while holding a photo of her father after reading his name as friends and relatives of the victims of the Sept. 11 terrorist attacks on the World Trade Center attend a ceremony marking the 11th anniversary of the attacks at the National September 11 Memorial at the World Trade Center site in New York, Tuesday, Sept. 11, 2012. (AP Photo/Jason DeCrow)

AP Photo/Jason DeCrow

Sept 11 Anniversary A girl becomes emotional after reading the name of her father as friends and relatives of the victims of the Sept. 11 terrorist attacks on the World Trade Center attend a ceremony marking the 11th anniversary of the attacks at the National September 11 Memorial at the World Trade Center site in New York, Tuesday, Sept. 11, 2012. (AP Photo/Jason DeCrow)

AP Photo/Jason DeCrow

Sept 11 Anniversary Friends and relatives of the victims of the Sept. 11 terrorist attacks on the World Trade Center attend a ceremony marking the 11th anniversary of the attacks at the National September 11 Memorial at the World Trade Center site in New York, Tuesday, Sept. 11, 2012.(AP Photo/Jason DeCrow)

AP Photo/Jason DeCrow

Sept 11 Anniversary Christine Box, right, the sister of firefighter Gary Box, and her daughter Nikki Silva hold posters during the observance of the anniversary of September 11 at the National September 11 Memorial in New York on Tuesday, Sept. 11, 2012. (AP Photo/Todd Maisel, Pool, New York Daily News)

AP Photo/Todd Maisel, Pool, New York Daily News

Sept 11 Anniversary An American flag is paced in one of the names of the victims of the Sept. 11 attacks, engraved at north reflecting pool of the World Trade Center Memorial, during the observance marking the 11th anniversary of the Sept. 11 attacks, in New York, Tuesday Sept. 11 2012. The One World Trade Center building is visible at background center. (AP Photo/Mike Segar, Pool)

AP Photo/Mike Segar, Pool

APTOPIX Sept 11 Anniversary Scott Willens, who joined the United States Army three days after the attacks on Sept. 11, 2001, pauses by the South Pool of the World Trade Center Memorial during the 11th anniversary observance, Tuesday, Sept. 11, 2012 in New York. (AP Photo/Justin Lane, Pool)

AP Photo/Justin Lane, Pool

Sept 11 Anniversary An American flag is inserted in one of the of names engraved at the north reflecting pool at the World Trade Center Memorial, during the 11th anniversary observance of the attacks at the World Trade Center, in New York, Sept. 11 2012. (AP Photo/Mike Segar, Pool)

AP Photo/Mike Segar, Pool

APTOPIX Sept 11 Anniversary One World Trade Center, center, rises above the National September 11 Memorial and Museum at the World Trade Center, Thursday, Sept. 6, 2012 in New York. Tuesday will mark the eleventh anniversary of the terrorist attacks of Sept. 11, 2001. The World Financial Center is on the left, and Four World Trade Center is at right. (AP Photo/Mark Lennihan)

AP Photo/Mark Lennihan

Sept 11 Anniversary Firefighters from New York City's Engine 8 and Ladder 2 stand on East 51st Street in front of their firehouse during a ceremony honoring fallen FDNY firefighters and victims on the 11th anniversary of the Sept. 11, 2001 terrorist attacks, Tuesday, Sept. 11, 2012 in New York. Ten members of the station died in the attack. (AP Photo/Charles Krupa)

AP Photo/Charles Krupa

Sept 11 Anniversary A firefighter's hat rests on names of firefighters at the south reflecting pool who died in the attacks at the World Trade Center, during the 11th anniversary observance at the World Trade Center Memorial in New York, Tuesday, Sept. 11, 2012. (AP Photo/Justin Lane, Pool)

AP Photo/Justin Lane, Pool

Sept 11 Anniversary Alicia Watkins remembers a friend who died at the Pentagon during a ceremony marking the 11th anniversary of the Sept. 11 attacks at the National September 11 Memorial at the World Trade Center site in New York, Tuesday, Sept. 11, 2012. (AP Photo/The Daily News, Todd Maisel, Pool)

AP Photo/The Daily News, Todd Maisel, Pool

Sept 11 Anniversary A young boy scratches the name on paper as friends and relatives of the victims of the Sept. 11 terrorist attacks on the World Trade Center attend a ceremony marking the 11th anniversary of the attacks at the National September 11 Memorial at the World Trade Center site in New York, Tuesday, Sept. 11, 2012. (AP Photo/The Daily News, Todd Maisel, Pool)

AP Photo/The Daily News, Todd Maisel, Pool

Sept 11 Anniversary Firefighters carry a flag as friends and relatives of the victims of the Sept. 11 terrorist attacks on the World Trade Center attend a ceremony marking the 11th anniversary of the attacks at the National September 11 Memorial at the World Trade Center site in New York, Tuesday, Sept. 11, 2012. (AP Photo/The Daily News, Todd Maisel, Pool)

AP Photo/The Daily News, Todd Maisel, Pool

Sept 11 Anniversary A man places flowers on a memorial site as friends and relatives of the victims of the Sept. 11 terrorist attacks on the World Trade Center attend a ceremony marking the 11th anniversary of the attacks at the National September 11 Memorial at the World Trade Center site in New York, Tuesday, Sept. 11, 2012. (AP Photo/The Daily News, Todd Maisel, Pool)

AP Photo/The Daily News, Todd Maisel, Pool

Sept 11 Anniversary Katie Pakenham, left, whose brother was killed in the attacks on the World Trade Center in 2001, and Teresa Methai, whose husband Joseph Methai was also killed, embrace each other as they stand in front of the Sept. 11 memorial on Boston Public Garden, following a wreath laying ceremony in Boston on the 11th anniversary of the attacks on Tuesday, Sept. 11, 2012. (AP Photo/Josh Reynolds)

AP Photo/Josh Reynolds

Sept 11 Anniversary New York City Police Dept. bugler Gabe Perdomo warms up while standing next to the South Pool of the World Trade Center Memorial during the 11th anniversary ceremony to mark the terrorist attacks on the World Trade Center in New York, Tuesday, Sept. 11, 2012. (AP Photo/Justin Lane, Pool)

AP Photo/Justin Lane, Pool

Dennis Swindell Dennis Swindell kisses the name of his partner Gary Lee Bright on the wall of the South Tower pool, during observances making the eleventh anniversary of the attacks at the World Trade Center, Tuesday, Sept. 11, 2012 in New York. (AP Photo/Timothy A. Clary, Pool)

AP Photo/Timothy A. Clary, Pool