Hundreds of red, white and blue LED modules are illuminating lower Manhattan as officials test the lights atop 1 World Trade Center.
The Port Authority of New York and New Jersey said Friday the beacon is packed with nearly 300 modules and their glow can be seen for up to 50 miles.
The beacon and spire together stand 408 feet tall and bring the building, formerly called the Freedom Tower, to its symbolic height of 1,776 feet.
The Durst Organization operates the spire, which will serve broadcasters.
A committee of world building heights experts met Friday in Chicago to decide whether a design change that affects the 408-foot needle disqualifies it from being counted as the nation's tallest skyscraper. The committee will announce its decision next week.