Each September, two large beams of light reach into the night sky above Manhattan's Financial District.
The installation commemorates those who were killed on September 11, 2001.
This Friday marks 25 years since that day, when terrorists hijacked four commercial passenger planes, crashing two into New York's Twin Towers.
Another plane hit the Pentagon in Arlington County, Virginia, and the fourth crashed into a field in Shanksville, Pennsylvania, after passengers attempted to overpower the hijackers.
In total, 2,977 victims lost their lives and, more than two decades later, their loved ones continue to gather to recite their names at the 9/11 Memorial at the World Trade Center complex in New York.
These photos show how the attacks destroyed the towers that once defined the city's skyline, and how New York rebuilt Ground Zero.
The Twin Towers dominated the New York City skyline on this June day in 1999.
Just over two years later, that skyline was horrifically altered.
The top photo was taken on August 30, 2001, while the bottom photo was taken 16 days after the attacks.
The first Tribute in Light occurred on March 11, 2002, across from Ground Zero.
In December 2003, a design for the new Freedom Tower was finally unveiled.
It would come to include multiple new buildings, such as the 1,776-foot-tall One World Trade Center and a 9/11 Memorial and Museum.
The Tribute in Light still shines each year on the roof of the Battery Parking Garage. Here it is, five years after the attacks.
In late 2007, the site still looked the same, as construction was hamstrung by lawsuits, budget overruns, design changes, and a recession.
In 2009, the 9/11 memorial waterfalls started to take shape.
One World Trade Center, also known as the "Freedom Tower," was just starting to rise from the rubble.
By July 2011, the memorial waterfalls were tested, and One World Trade Center's facade was beginning to reflect the sky.
The memorial waterfalls officially opened in September 2011, and the museum, seen on the right, opened in May 2014.
By November 2014, One World Trade Center was complete, as were 4 World Trade Center (left) and 7 World Trade Center (right). However, 3 World Trade Center still wasn't finished.
The WTC Transportation Hub, on which the white Oculus was built, was also under construction in late 2014.
The hub officially opened in June 2016, while 3 World Trade Center was still under construction.
The $50 million Liberty Park also opened in June 2016. From there, visitors can get an overhead view of the Ground Zero memorial.
This photo from June 2018 shows 3 World Trade Center, One World Trade Center, 4 World Trade Center, the 9/11 Memorial and Museum, and Liberty Park, all of which were finally complete.
With construction officially complete, the Manhattan skyline is now forever changed.
Now the tallest building in the US, the gleaming One World Trade Center, pictured in August 2025, towers over the Financial District.
The Tribute of Light was tested ahead of the 25th anniversary of 9/11.
Daniel Brown contributed to an earlier version of this article.
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Ellen Ioanes is the Military & Defense Editorial Fellow at INSIDER. She is a graduate of Columbia Journalism School and Davidson College. Her work appears in the Guardian, the Center for Public Integrity, the Daily Dot, HuffPost India, and more. You can follow her on Twitter @girlstothefront.
Roya is a reporter on Business Insider's Editorial Partnerships team. She is based in London. Before joining Business Insider, she worked as a reporter at financial newswire Alliance News and was an intern at The Wall Street Journal. Roya graduated from City St George's, University of London with an MA in International Journalism.
