In Pictures: Michelle Obama in Haiti and Mexico
In Pictures: Obama's Asia trip
In Pictures: Inside President Obama's White House
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In Pictures: Obama family vacations
In Pictures: President Obama in Afghanistan
A visitor to the National September 11 Memorial get a view of one of the memorial pools and One World Trade Center, center, June 14, 2012 in New York. President Barack Obama is scheduled to visit the site. Mark Lennihan/AP
US President Barack Obama, first lady Michelle Obama, former president George W. Bush and Laura Bush salute the flag during tenth anniversary ceremonies at the National September 11 Memorial at the World Trade Center site in New York, September 11, 2011. Allan Tannenbaum/Reuters
The National September 11 Memorial and Museum under construction, at the World Trade Center site in New York, May 3, 2011. The memorial was opened to the public in time for the tenth anniversary, Sept. 11, 2011. Mark Lennihan/AP/File
President Barack Obama waves as he steps off Air Force One at John F. Kennedy International Airport in New York, on May 5, 2011, en route to Ground Zero. Charles Dharapak/AP
President Barack Obama greets guests after arriving at John F. Kennedy International Airport in New York, May 5, 2011. Henny Ray Abrams/AP
President Barack Obama salutes as he boards Air Force One at Andrews Air Force Base, Md., May 5, 2011, before traveling to New York City. Charles Dharapak/AP
Ground Zero is seen from the north side of the site, on May 5, 2011, in New York, ahead of a visit by President Barack Obama to lay a wreath and meet with victims' families. Seth Wenig/AP
Workers prepare the area near the 'survivor tree' at the World Trade Center site in New York on May 4, 2011. Brendan McDermid/Reuters
Bill Steyert of Queens waits outside Ground Zero for President Barack Obama's visit to the World Trade Center site in New York, on May 5, 2011. Mike Segar/Reuters
New York City police officers stand guard outside Ground Zero ahead of President Barack Obama's visit, on May 5, 2011, in New York. Obama arrived in New York for a solemn visit to Ground Zero in an attempt bury the memory of Osama bin Laden by honoring those who died in the Sept. 11 attacks on the World Trade Center. Mary Altaffer/AP
President Barack Obama speaks to firefighters and first responders at Engine 54, Ladder 4, Battalion 9 before visiting the National Sept. 11 Memorial at Ground Zero in New York, on May 5, 2011. Charles Dharapak/AP
President Barack Obama meets with firefighters and first responders at Engine 54, Ladder 4, Battalion 9 before visiting the National Sept. 11 Memorial at Ground Zero in New York, on May 5, 2011. Charles Dharapak/AP
President Barack Obama's limousine is parked as he meets with firefighters and first responders at Engine 54, Ladder 4, Battalion 9, May 5, 2011. Charles Dharapak/AP
President Barack Obama carries a wreath accompanied by New York City firefighters and NYPD police officers during a wreath laying ceremony at Ground Zero, May 5, 2011. Brendan McDermid/Reuters
President Barack Obama pauses after laying a wreath at Ground Zero, May 5, 2011. Charles Dharapak/AP
President Barack Obama meets with Avery Wall (l.) and her sister Payton, whose father died in the attacks at the World Trader Center, during a wreath laying ceremony, May 5, 2011. Richard Drew/AP
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4 World Trade Center: BeBe Winans sang "God Bless America" and more than 100 workers signed the final steel beam. 4 World Trade Center will be the first tower rebuilt after the Sept. 11 attacks.
A final steel beam was lifted Monday atop a new World Trade Center skyscraper — the first expected to open at the site next year since the twin towers were decimated on 9/11.
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