The 9/11 Memorial Museum tested out the "Tribute in Light" Wednesday ahead of the anniversary of the attacks.
The tribute first debuted on March 11, 2002, just six months after the attacks.
It has shined bright over Lower Manhattan every year on the solemn anniversary.
The memorial is made up of 88 searchlights positioned to represent the Twin Towers.
They will be lit once again after sundown this Sunday and stay up through the overnight hours until dawn.