Family members visit the South Pool of the 9/11 Memorial during the tenth anniversary ceremonies of the September 11, 2001 terrorist attacks at the World Trade Center site.
(Photo by Todd Heisler-Pool/Getty Images)
(Photo by Todd Heisler-Pool/Getty Images)Family members visit the South Pool of the 9/11 Memorial during the tenth anniversary ceremonies of the September 11, 2001 terrorist attacks at the World Trade Center site.
(Photo by Mario Tama/Getty Images)A firefighter places an American flag on a memorial display while preparing for 9/11 ceremonies at FDNY Ladder 20 Engine 13 on September 9, 2011 in New York City. Ladder 20 lost seven firefighters on September 11, 2001.
(Photo by Mario Tama/Getty Images)The Tribute in Light near the World Trade Center site is seen from the Empire State Building September 11, 2006 in New York City.
(Photo by Justin Lane-Pool/Getty Images)Robert Peraza, who lost his son Robert David Peraza, pauses at his son's name at the North Pool of the 9/11 Memorial during tenth anniversary ceremonies at the site of the World Trade Center on September 11, 2011, in New York City.
(Photo by Jeff Swensen/Getty Images)U.S. Secretary of Defense Leon Panetta (R) tours the Flight 93 National Memorial with Families of Flight 93 President Patrick White during ceremonies commemorating the eleventh anniversary of the 9/11 attacks, September 10, 2012 in Shanksville, Pennsylvania.
(Photo by David Handschuh-Pool/Getty Images)New York City Police Officer Danny Shea, a military vet, salutes at the North pool of the 9/11 Memorial during the tenth anniversary ceremonies of the September 11, 2001 terrorist attacks.
(Photo by Drew Angerer/Getty Images)Retired New York City firefighter Bruce Stanley holds a portrait of his late friend Liam Smith Jr., a New York City firefighter who died in the 9/11 attacks.
(Photo by Archie Carpenter/Getty Images)A mother holds her daughter as the sun sets behind them at the temporary memorial for the crash of Flight 93 on September 11, 2004 near Shankville, Pennsylvania.
(Photo by Chris Hondros/Getty Images)Two columns of light symbolize the fallen World Trade Center towers in a tribute.
(Photo by Drew Angerer/Getty Images)An American flag is left at the North pool memorial site before a commemoration ceremony for the victims of the September 11 terrorist attacks at the National September 11 Memorial, September 11, 2017 in New York City.
(Photo by Justin Sullivan/Getty Images)Nancy Ricci stops to touch a tile on a memorial for the 343 New York firefighters who died during the September 11 terror attacks.
(Photo by Justin Lane-Pool/Getty Images)Family members gather at the edge of the North Pool of the 9/11 Memorial during the tenth anniversary ceremonies of the September 11, 2001 terrorist attacks at the World Trade Center site, September 11, 2011 in New York City. New York City and the nation are commemorating the tenth anniversary of the terrorist attacks.
(Photo by Justin Sullivan/Getty Images)Workers adjust beams of the Tribute in Lights ahead of the tenth anniversary of the September 11 terrorist attacks on September 7, 2011 in New York City. The Tribute in Light is comprised of 88 7000 watt searchlights that beam into the sky near the site of the World Trade Center in remembrance of the September 11 attacks.
(Photo by Chris Hondros/Getty Images)Two columns of light symbolize the fallen World Trade Center towers in a tribute in light as seen from New Jersey September 11, 2003 in New York City.
(Photo by David Handschuh-Pool/Getty Images)President Barack Obama (2R), first lady Michelle Obama (3R), former President George W. Bush (L) and former first lady Laura Bush (4L) with their daughters Jenna Bush Hager (2L) and Barbara Bush (3L) and Henry Hager (R) look out at the North Pool of the 9/11 Memorial during the tenth anniversary ceremonies of the September 11, 2001 terrorist attacks at the World Trade Center site,
(Photo by Justin Lane-Pool/Getty Images)A New York City police officer salutes at the North Pool of the 9/11 Memorial during the tenth anniversary ceremonies of the September 11, 2001 terrorist attacks at the World Trade Center site, September 11, 2011 in New York City.
