Remembering 9/11 People evacuate the area around the World Trade Center after it was hit by two planes September 11, 2001 in New York City. (Photo by Mario Tama/Getty Images) (Mario Tama/Getty Images)
Remembering 9/11 An unidentified New York City firefighter walks away from Ground Zero after the collapse of the Twin Towers on September 11, 2001 in New York City. The World Trade Center's Twin Towers and the Pentagon were attacked by terrorists using commercial airliners as missiles. (Photo by Anthony Correia/Getty Images) (Anthony Correia/Getty Images)
Remembering 9/11 Smoke comes out from the west wing of the Pentagon building September 11, 2001 in Arlington, Va., after a plane crashed into the building and set off a huge explosion. (Photo by Alex Wong/Getty Images) (Alex Wong/Getty Images)
Remembering 9/11 Early morning light hits the smoke and wreckage of the World Trade Center September 13, 2001 in New York City, two days after the twin towers were destroyed when hit by two hijacked passenger jets. (Photo by Chris Hondros/Getty Images) (Chris Hondros/Getty Images NA)
Remembering 9/11 Civilians flee the area as a tower of the World Trade Center collapses September 11, 2001 in New York City after two airplanes slammed into the twin towers in an alleged terrorist attack. (Photo by Spencer Platt/Getty Images) (Spencer Platt/Getty Images NA)
Remembering 9/11 People walk in the street in the area where the World Trade Center buildings collapsed September 11, 2001 after two airplanes slammed into the twin towers in a terrorist attack. (Photo by Mario Tama/Getty Images) (Mario Tama/Getty Images)
Remembering 9/11 U.S. President George W. Bush holds an American flag during a Memorial Service at the Pentagon October 11, 2001 in Arlington, Virginia. (Photo by Mark Wilson/Getty Images) (Getty Images/Getty Images)
Remembering 9/11 A New York City fireman calls for 10 more rescue workers to make their way into the rubble of the World Trade Center September 14, 2001 days after the September 11, 2001 terrorist attack. (U.S. Navy Photo by Preston Keres/Getty Images) (U.S. Navy/Getty Images)
Remembering 9/11 Firefighters walk towards one of the towers at the World Trade Center before it collapsed after a plane hit the building September 11, 2001 in New York City. (Photo by Jose Jimenez/Primera Hora/Getty Images) (Jose Jimenez/Primera Hora/Getty Images NA)
Remembering 9/11 Remnants of a New York City Fire Department vehicle lie in the wreckage of the World Trade Center September 13, 2001 in New York City, two days after the twin towers were destroyed when hit by two hijacked passenger jets. (Photo by Chris Hondros/Getty Images) (Chris Hondros/Getty Images NA)
Remembering 9/11 A man watches smoke emit from the former site of the World Trade Center September 12, 2001 in Hoboken, N.J. Smoke filled the air all over lower Manhattan in the aftermath of Tuesday's terrorist attack and destruction of the World Trade Center. (Photo by Chris Hondros/Getty Images) (Chris Hondros/Getty Images)
Remembering 9/11 Fires still burn amidst the rubble of the World Trade Center September 13, 2001 days after the September 11, 2001 terrorist attack. (U.S. Navy Photo by Jim Watson/Getty Images) (U.S. Navy/Getty Images)
Remembering 9/11 A rescue worker is pulled from the rubble of the World Trade Center September 13, 2001 in New York City two days after two hijacked airplanes slammed into the twin towers, leveling them and killing nearly 3,000 people. (Photo by Mario Tama/Getty Images) (Mario Tama/Getty Images NA)
Remembering 9/11 New York City firefighters take a rest at the World Trade Center after two hijacked planes crashed into the Twin Towers September 11, 2001 in New York. (Photo by Ron Agam/Getty Images) (Ron Agam/Getty Images)
Remembering 9/11 Firefighters stand atop a fire engine with the flag-draped casket of fellow fireman Lt. Dennis Mojica September 21, 2001 during a funeral service at St. Patrick's Cathedral in New York City. Mojica, who was with Rescue Company 1, is one of nearly 300 firefighters who lost their lives in the World Trade Center disaster. (Photo by Joe Raedle/Gettyimages) (Joe Raedle/Getty Images)
Remembering 9/11 Smoke pours from the twin towers of the World Trade Center after they were hit by two hijacked airliners in a terrorist attack September 11, 2001 in New York City. (Photo by Robert Giroux/Getty Images) (Robert Giroux/Getty Images)
Remembering 9/11 People evacuate the area around the World Trade Center after it was hit by two planes September 11, 2001 in New York City. (Photo by Mario Tama/Getty Images) (Mario Tama/Getty Images)
Remembering 9/11 Rescue workers and Pentagon personnel attend to the wounded outside the Pentagon after a hijacked plane crashed into the building September 11, 2001 in Washington, DC. (Photo by Greg Whitesell/Getty Images) (Greg Whitesell/Getty Images)
Remembering 9/11 People run away as the North Tower of World Trade Center collapses after a hijacked airliner hit the building September 11, 2001 in New York City. (Photo by Jose Jimenez/Primera Hora/Getty Images) (Jose Jimenez/Primera Hora/Getty Images)
Remembering 9/11 Firefighter Tony James cries while attending the funeral service for New York Fire Department Chaplain Rev. Mychal Judge, in front of the St. Francis of Assisi Church September 15, 2001 in New York City. Judge died while giving the last rites to a fireman in the collapse of the World Trade Center. The World Trade Center was destroyed after both the landmark towers were struck by two hijacked planes in a terrorist attack on September 11. (Photo by Joe Raedle/Getty Images) (Joe Raedle/Getty Images NA)
Remembering 9/11 Rescue workers sift through the wreckage of the World Trade Center September 13, 2001 in New York City, two days after two hijacked airplanes slammed into the twin towers, leveling them in an alleged terrorist attack. (Photo by Mario Tama/Getty Images) (Mario Tama/Getty Images NA)
Remembering 9/11 A military helicopter flies in front of the Pentagon September 14, 2001 in Arlington, Virginia at the impact site where a hijacked airliner crashed into the building. (Photo by Stephen J. Boitano/Getty Images) (Stephen J. Boitano/Getty Images)
Remembering 9/11 An injured man gets some help after being taken out of the Pentagon after a plane crashed into the building September 11, 2001 in Arlington, VA. (Photo by Mark Wilson/Getty Images) (Mark Wilson/Getty Images)
Remembering 9/11 Civilians take cover as a dust cloud from the collapse of the World Trade Center envelops lower Manhattan, September 11, 2001. (Photo by Mario Tama/Getty Images) (Mario Tama/Getty Images)
Remembering 9/11 A survivor sits outside the World Trade Center after two planes hit the building September 11, 2001 in New York City. (Photo by Jose Jimenez/Primera Hora/Getty Images) (Angela Jimenez/Getty Images)
Remembering 9/11 Smoke comes out from the Southwest E-ring of the Pentagon building September 11, 2001 in Arlington, Va., after a plane crashed into the building and set off a huge explosion. (Photo by Alex Wong/Getty Images) (Alex Wong/Getty Images)
Remembering 9/11 Hijacked United Airlines Flight 175 from Boston crashes into the south tower of the World Trade Center and explodes at 9:03 a.m. on September 11, 2001 in New York City. The crash of two airliners hijacked by terrorists loyal to al Qaeda leader Osama bin Laden and the subsequent collapse of the twin towers killed some 2,800 people. (Photo by Spencer Platt/Getty Images) (Spencer Platt/Getty Images)
Remembering 9/11 People watch World Trade Center burn September 11, 2001 after two hijacked airplanes slammed into the twin towers in New York City. (Photo by Spencer Platt/Getty Images) (Spencer Platt/Getty Images)
Remembering 9/11 Firefighter Gerard McGibbon, of Engine 283 in Brownsville, Brooklyn, prays after the World Trade Center buildings collapsed September 11, 2001 after two hijacked airplanes slammed into the twin towers in a terrorist attack that killed some 3,000 people. (Photo by Mario Tama/Getty Images) (Mario Tama/Getty Images NA)
Remembering 9/11 Mounted police make their way along an access road leading to the crash site of United Airlines Flight 93 through the early morning fog 12 September 2001 in Shanksville, Pennsylvania. The plane was hijacked and crashed killing all 45 on board. AFP PHOTO/David MAXWELL (Photo credit should read DAVID MAXWELL/AFP via Getty Images) (DAVID MAXWELL/AFP via Getty Images)
Remembering 9/11 This photo taken 12 September 2001 shows the crash site of United Airlines Flight 93 in Shanksville, PA. The plane from Newark, NJ, bound for San Francisco, CA, was hijacked, and crashed in a field in Shanksville. Forty-five people were on board the plane, and there were no survivors. AFP PHOTO/David MAXWELL (Photo credit should read DAVID MAXWELL/AFP via Getty Images) (DAVID MAXWELL/AFP via Getty Images)
Remembering 9/11 Pennsylvania State Troopers stand guard 11 September 2001 at the crash site of United Airlines Flight 93 in Shanksville, Pennsylvania. The plane from Newark, New Jersey, and bound for San Francisco, California, was hijacked and crashed. There were no survivors. AFP PHOTO/David MAXWELL
(Photo credit should read DAVID MAXWELL/AFP via Getty Images) (DAVID MAXWELL/AFP via Getty Images)
Remembering 9/11 Officials examine the crater 11 September 2001 at the crash site of United Airlines Flight 93 in Shanksville, Pennsylvania. The plane from Newark, New Jersey, and bound for San Francisco, California, is believed to have been hijacked and crashed in the field killing all on board. AFP PHOTO/David MAXWELL (Photo credit should read DAVID MAXWELL/AFP via Getty Images) (DAVID MAXWELL/AFP via Getty Images)
Remembering 9/11 An unidentified Pennsylvania State Trooper stands guard 11 September 2001 at the crash site of United Airlines Flight 93 in Shanksville, Pennsylvania. The mound of dirt in the center of the field is the crater made by the plane's impact. The plane from Newark, New Jersey, and bound for San Francisco, California, was hijacked and crashed in the field. Forty-five people were on board the plane, and there were no survivors. AFP PHOTO/David MAXWELL (Photo credit should read DAVID MAXWELL/AFP via Getty Images) (DAVID MAXWELL/AFP via Getty Images)
Remembering 9/11 A visitor looks over a memorial to the victims of United Airlines Flight 93 near the site of the plane crash in Shanksville, Pennsylvania, 20 September, 2001. Flight 93 crashed in a field during a coordinated terrorist attack on the US 11 September. AFP PHOTO/David MAXWELL (Photo credit should read DAVID MAXWELL/AFP via Getty Images) (DAVID MAXWELL/AFP via Getty Images)
Remembering 9/11 Officials examine the crater 11 September 2001 at the crash site of United Airlines Flight 93 in Shanksville, Pennsylvania. The plane from Newark, New Jersey, and bound for San Francisco, California, was hijacked and crashed in the field killing all people on board. AFP PHOTO/David MAXWELL (Photo by DAVID MAXWELL / AFP) (Photo by DAVID MAXWELL/AFP via Getty Images) (DAVID MAXWELL/AFP via Getty Images)
Remembering 9/11 A mound of dirt and charred trees (right) mark the site of a crater created by the impact of United Airlines Flight 93, which crashed 11 September, 2001. The plane from Newark, New Jersey, bound for San Francisco, California, was hijacked, and crashed in a field in Shanksville, Pennsylvania, and was part of the coordinated terrorist attacks on New York and Washington, DC. Forty-five people were reported to be on the plane. AFP PHOTO/David MAXWELL
(Photo credit should read DAVID MAXWELL/AFP via Getty Images) (DAVID MAXWELL/AFP via Getty Images)
Remembering 9/11 A National Transportation Safety Board worker walks by an FBI trailer at the crash site of United Airlines Flight 93 in Shanksville, PA,12 September 2001. The plane from Newark, NJ, bound for San Francisco, CA, was hijacked, and crashed in a field in Shanksville. Forty-five people were on board the plane, and there were no survivors. AFP PHOTO/David MAXWELL (Photo by DAVID MAXWELL / AFP) (Photo by DAVID MAXWELL/AFP via Getty Images) (DAVID MAXWELL/AFP via Getty Images)
