In what has become one of the most moving — and visible — 9/11 memorials, two giant pillars of light near where the World Trade Center’s twin towers once stood were turned on in lower Manhattan this week to mark the 15th anniversary of the Sept. 11, 2001, terrorist attacks.

The Tribute in Light art installation consists of 88 searchlights that create two vertical columns of light.

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The Tribute in Light rises above the New York skyline from West Broadway with One World Trade Center to the right on Sept. 10, 2016. (Gordon Donovan/Yahoo News) The Tribute in Light rises above the New York skyline near the National September 11 Memorial & Museum on Sept. 10, 2016. (Gordon Donovan/Yahoo News) A woman takes a photo of the Tribute in Light with her mobile device at the National September 11 Memorial & Museum on Sept. 10, 2016. (Gordon Donovan/Yahoo News)
The Tribute in Light rises above the New York City skyline from the National September 11 Memorial & Museum on Sept. 10, 2016, the 15th anniversary of the 2001 terrorist attacks. (Gordon Donovan/Yahoo News) The Tribute in Light rises above the New York City skyline from the National September 11 Memorial & Museum on Sept. 10, 2016, the 15th anniversary of the 2001 terrorist attacks. (Gordon Donovan/Yahoo News) The Tribute in Light rises above the New York City skyline from the National September 11 Memorial & Museum on Sept. 10, 2016, the 15th anniversary of the 2001 terrorist attacks. (Gordon Donovan/Yahoo News)
A visitor takes a photo of the Tribute in Light at the National September 11 Memorial & Museum on Sept. 10, 2016. (Gordon Donovan/Yahoo News) The Tribute in Light rises above the New York City skyline from the National September 11 Memorial & Museum on Sept. 10, 2016, the 15th anniversary of the 2001 terrorist attacks. (Gordon Donovan/Yahoo News) Flowers and flags lay on top of one of the panels at the North Pool of National September 11 Memorial & Museum as the Tribute in Light rises above the New York skyline on Sept. 10, 2016. (Gordon Donovan/Yahoo News)
The Tribute in Light rises above the New York skyline on Sept. 10, 2016. (Gordon Donovan/Yahoo News) The Tribute in Light art installation consists of 88 searchlights that create two vertical columns of light on Sept. 10, 2016. (Gordon Donovan/Yahoo News) The Tribute in Light rises above the New York City skyline from the rooftop of where the installation was projected on Sept. 10, 2016, the 15th anniversary of the 2001 terrorist attacks. (Gordon Donovan/Yahoo News)
Taken on his back using a fisheye lens, The Tribute in Light rises above the New York skyline from the National September 11 Memorial & Museum on Sept. 10, 2016. (Gordon Donovan/Yahoo News) The Tribute in Light rises above the New York skyline from the National September 11 Memorial & Museum on Sept. 10, 2016. (Gordon Donovan/Yahoo News) In a photo taken with a fisheye lens, the two beams of light meet in the art installation "The Tribute in Light" projecting in the night sky over Manhattan on Sept. 10, 2016. (Gordon Donovan)
The Tribute in Light art installation consists of 88 searchlights that create two vertical columns of light on Sept. 10, 2016. (Gordon Donovan/Yahoo News) People stand and inside the art installation of The Tribute in Light on Sept. 10, 2016. (Gordon Donovan/Yahoo News) A woman takes a photo of the Tribute in Light with her mobile device from the roof top of where the beams of lights are projected on Sept. 10, 2016. (Gordon Donovan/Yahoo News)
The Tribute in Light rises above the Trinity Church on Broadway, Sept. 10, 2016. (Gordon Donovan/Yahoo News) The Tribute in Light rises above the New York skyline from the Canyon of Heroes on Sept. 10, 2016. (Gordon Donovan/Yahoo News) The Tribute in Light rises above the New York skyline from the Brooklyn Bridge on Sept. 10, 2016. (Gordon Donovan/Yahoo News)

Photos taken September 2016, 2010 using a Canon EOS-1D X DSLR with a Canon EF 24-70mm f/2.8L II USM Standard Zoom Lens, Canon EF 8-15mm f/4L Fisheye USM Lens.