9/11 Then and Now

Shown in this combo image are two documentations of the before and after of the September 11, 2001, terrorist attack in New York City. (Top) New Yorkers walk over the Brooklyn Bridge on their way to work, April 7, 1980, during the transit strike. (Below) People flee the scene of the attacks on the World Trade center on September 11, 2001. (AP Photo/Carlos Rene Perez (Top), Mark Lennihan(Bottom))

Shown in this combo image are two documentations of the September 11, 2001, terrorist attack in New York City and the current day location. (Top) The World Trade Center destruction is shown in the aftermath of the Sept. 11 attacks in New York on Sept. 30, 2001. (Below) The tower known as Four World Trade Center is under construction in lower Manhattan, Aug. 9, 2011 in New York. (AP Photos/Mark Lennihan)

Shown in this combo image are two documentations of the before and after of the September 11, 2001, terrorist attack in New York City. (Top) This general view shows the World Trade Center twin towers as construction continues on the buildings at Church Street between Vesey and Liberty Streets in lower Manhattan, New York City, on Jun 13, 1970. (Below) This photo taken Sept. 11, 2001 by the New York City Police Department shows smoke and ash engulfing the area around the World Trade Center in New York. (AP Photo/ Marty Lederhandler (Top), Greg Semendinger(Bottom))

Shown in this combo image are two documentations of the September 11, 2001, terrorist attack in New York City and the current day location. (Top) 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. (Below) Pedestrians pass the Hilton Hotel on Church St. in lower Manhattan, Aug. 4, 2011, in New York. (AP Photos/Mark Lennihan))

Shown in this combo image are two documentations of the September 11, 2001, terrorist attack in New York City and the current day location. (Top) Firefighters work beneath the destroyed mullions, the vertical struts which once faced the soaring outer walls of the World Trade Center towers, after a terrorist attack on the twin towers of lower Manhattan Tuesday, Sept. 11, 2001. (Below) The tower known as Four World Trade Center is under construction in lower Manhattan, Aug. 4, 2011 in New York. (AP Photo/ Mark Lennihan)

FILE - In this Sept. 11, 2001 file photo, the twin towers of the World Trade Center burn after hijacked planes crashed into them in New York. As the post-Sept. 11 decade ends, some foreign families of the victims are eager to move past the tragedy. But though the pain transcended borders, foreign families have battled to cope with their loss from afar. (AP Photo/Diane Bondareff, File)

FILE - In this Sept. 11, 2001, file photo, plumes of smoke rise from the World Trade Center buildings in New York. The Empire State building is seen in the foreground. Television viewers who want to immerse themselves in memories of the Sept. 11 terrorist attacks as the 10th anniversary approaches will have a staggering number of choices, and on the day itself, broadcast and cable news networks will all have their top talent on hand for special coverage. (AP Photo/Patrick Sison, File)

Shown in this combo image are two documentations of the September 11, 2001, terrorist attack in New York City and the current day location. (Top) A street near ground zero on the evening of September 11, 2001 after the September 11 terrorist attacks on the World Trade Center in New York City. (Below) Pedestrians pass a McDonald's restaurant on Broadway in lower Manhattan, Aug. 4, 2011, in New York. (AP Photos/Mark Lennihan)

Shown in this combo image are two documentations of the September 11, 2001, terrorist attack in New York City and the current day location. (Top) Smoke rises into the sky following the collapse of World Trade Center Towers Tuesday, Sept. 11, 2001 in New York. (Below) The skyscraper known as One World Trade Center rises in lower Manhattan, Aug. 10, 2011 in New York. (AP Photo/ Suzanne Plunkett (Top), Mark Lennihan (Bottom))

Shown in this combo image are two documentations of the September 11, 2001, terrorist attack in New York City and the current day location. (Top) Pedestrians flee the area of the World Trade Center as the center's south tower collapses following a terrorist attack on the New York landmark Tuesday, Sept. 11, 2001. (Below) The skyscraper known as 1 World Trade Center is under construction in lower Manhattan, Aug. 4, 2011 in New York. (AP Photos/ Mark Lennihan)

Shown in this combo image are two documentations of the September 11, 2001, terrorist attack in New York City and the current day location. (Top) Emergency workers at ground zero on Sept. 11, 2001 after the terrorist attacks on the World Trade Center in New York City.(Below) Pedestrians walk along Church St. past Century 21 clothing store in lower Manhattan, Aug. 4, 2011, in New York. (AP Photos/Mark Lennihan)

Shown in this combo image are two documentations of the September 11, 2001, terrorist attack in New York City and the current day location. (Top) People covered in dust walk over debris near the World Trade Center in New York. (Below) Pedestrians walk near the World Trade Center in lower Manhattan, Aug. 8, 2011 in New York. (AP Photo/ Gulnara Samilova (Top), Mark Lennihan (Bottom))

Shown in this combo image are two documentations of the September 11, 2001, terrorist attack in New York City and the current day location. (Top) A destroyed subway station near ground zero on the evening of Sept. 12, 2001 after the September 11 terrorist attacks on the World Trade Center in New York City.(Below) Pedestrians walk along Church St. in lower Manhattan, Aug. 4, 2011 in New York. Behind them is the tower known as Four World Trade Center. (AP Photo/ Mark Lennihan)

Shown in this combo image are two documentations of the September 11, 2001, terrorist attack in New York City and the current day location. (Top) The south tower starts to collapse as smoke billows from both buildings of the World Trade Center in New York. (Below) The skyscraper known as One World Trade Center rises in the lower Manhattan skyline, Aug. 4, 2011 in New York. (AP Photo/ Jim Collins (Top), Mark Lennihan (Bottom))

Shown in this combo image are two documentations of the before and after of the September 11, 2001, terrorist attack in New York City. (Top) The Statue of Liberty and the New York skyline frame warships and smaller craft for Operation Sail in this helicopter view on Saturday, July 3, 1976. (Below) 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/ ETA (Top), Daniel Hulshizer(Bottom))

Shown in this combo image are two documentations of the September 11, 2001, terrorist attack in New York City and the current day location. (Top) Pedestrians flee the area of the World Trade Center as the center's south tower collapses following a terrorist attack on the New York landmark Tuesday, Sept. 11, 2001. (Below) Activity on Park Row is shown in lower Manhattan, Aug. 4, 2011 in New York. (AP Photos/Mark Lennihan)

Shown in this combo image are two documentations of the before and after of the September 11, 2001, terrorist attack in New York City. (Top) The Brooklyn Bridge is seen spanning over New York's East River, with the twin towers of the World Trade Center in the background, June 12, 1990. (Below) Smoke rises behind the Brooklyn Bridge over the East River frames the skyline of Manhattan, minus the World Trade towers, as seen from Brooklyn early Wednesday, Sept. 12, 2001, the day after hijacked airplanes crashed into both buildings causing their collapse on Tuesday. (AP Photo/Marty Lederhandler(Top), Kathy Willens(Bottom))

A view of the World Trade Center North Tower memorial pool at the National September 11 Memorial and Museum in New York,Tuesday, Sept. 6, 2011. (AP Photo/Susan Walsh, POOL)

A view of the World Trade Center North Tower memorial pool at the National September 11 Memorial & Museum New York,Tuesday, Sept. 6, 2011. (AP Photo/Susan Walsh, POOL)