Photos by Space Imaging’s IKONOS satellite showing the World Trade Center complex in Manhattan, New York, collected on June 30, 2001 showing the 110-stories twin towers; on September 15, 2001 showing the remains of the 1,350-foot (411.48-meter) twin towers of the World Trade Center, and the debris and dust that have settled in Ground Zero, four days after the terrorist attacks; and June 8, 2002, showing the progress in the reclamation of Ground Zero where the twin towers of the World Trade Center once stood. AFP/Space Imaging

The twin towers of World Trade Center burn after two planes crashed into each on September 11th. (STAN HONDA/AFP/Getty Images)

A man stands in the rubble, and calls out asking if anyone needs help, shortly after the collapse of the first World Trade Center Tower 11 September, 2001, in New York City. (DOUG KANTER/AFP/Getty Images)

Firefighters make their way through the rubble of the World Trade Center Tower 11 on September 11th, 2001. (DOUG KANTER/AFP/Getty Images)

Sunlight filtered into the still smoldering remains of Tower Two as workers riding in a basket suspended from a giant crane hovered above on Oct. 27, 2001. William C. Lopez/Associated Press

A worker dismantled the T-shaped steel beam, which gained fame as the ground zero cross, on Oct. 5, 2006. The cross was found by a construction worker amid smoking ruins two weeks after the Sept. 11 attacks. Bebeto Matthews/Associated Press

Construction continued at the World Trade Center site with the memorial footprints of the twin towers visible on Sept. 7, 2010. Mario Tama/Getty Images

The World Trade Center ceremony marking the 10th anniversary of the attacks takes place at the National September 11 Memorial, Sept. 11, 2011 in New York. Mark Lennihan/Associated Press

A framed photo of the Twin Towers sits against a curb in honor of a 9/11 victim near Ground Zero during the 10th anniversary ceremony, September 11, 2011, in New York. Tom Fox/The Dallas Morning News

Lights illuminated ground zero as the sun set over the Manhattan on Sept. 6, 2002. Vincent LaForet/The New York Times

Beaming: The art installation was switched on for the first time this year on Tuesday evening, as preparations for the tenth anniversary of 9/11 on Sunday started (Getty Images)

Iconic: The Municipal Art Society developed the project in the aftermath of 9/11 and first switched on the brilliant beacons to mark the six-month anniversary of the attacks (AP)

Ablaze: The Tribute in Light’s 88 powerful searchlights will project upwards from Ground Zero from dusk on September 11 until dawn on September 12 (Getty Images)

Commemoration: The intense lights will pierce the night sky for the ninth year in a row, but organizers say the event is under threat because of a lack of funds (AP)

Tribute in Lights by Dan Greenberg