Tenth Anniversary of 9/11 at Ground Zero in New York

U.S. President Barack Obama, First Lady Michelle Obama, Former U.S. President George W. Bush and former First Lady Laura Bush walk by one of the memorial Pools as people wait to visit the site on the tenth anniversary of the terrorist attacks on the World Trade Center on 9/11 at Ground Zero in New York City on September 11, 2011. UPI/John Angelillo