One World Trade Centre, Lower Manhattan, New York City, New York, United States

On December 16, 2010, the Port Authority announced that the tower's construction had reached the 52nd floor, rising to over 600 feet (180 m) and marking the halfway point for the tower's steel frame. By September 11, 2011, ten years after the destruction of the original World Trade Center, the tower's steel had reached the 82nd floor, while its concrete flooring had reached the 72nd floor, and glass cladding had reached the 56th floor.
While under construction, the tower was specially illuminated on several occasions. On the weekend of July 4, 2011, it was lit up in the colors of the American flag to commemorate Independence Day, and it was lit up in the same colors on September 10 to mark the 10th anniversary of the September 11 terrorist attacks. On October 27, it was illuminated in pink in honor of Breast Cancer Awareness Month. On December 11, the Port Authority illuminated the tower in multicolored lights to celebrate the holiday season. On February 24, 2012, the building was lit up in red in honor of Archbishop of New York Timothy Dolan, who became a cardinal on February 18. On June 14, 2012, it was illuminated in red, white, and blue to honor Flag Day. In August, it was illuminated in red in honor of the Armed Forces. On September 8, 2012, it was again illuminated in red, white, and blue to honor the 11th anniversary of the September 11 attacks. On June 24, 2013, One World Trade Center was again illuminated in red, white, and blue to celebrate the Fourth of July. On November 12, 2013, three hundred red, white, and blue lights were lit up.
On January 31, 2012, the Port Authority stated that the tower's loading dock would not be finished in time to move equipment into the completed building, and that five temporary loading bays would be added instead, at a cost of millions. The temporary Trans Hudson station will not be removed until its replacement is completed, preventing access to the planned loading area. By March 2012, One World Trade Center's steel had reached the 93rd floor, and on March 30, the 100th floor was reached at a height of 1,240 feet (380 m). Though this floor was numbered as floor 100, it was in fact the 94th floor constructed since the intervening space was occupied by the high-ceilinged mechanical 91st floor. The incomplete tower became New York City's tallest building by roof height, superseding the 1,250-foot (380 m) roof height of the Empire State Building, on April 30, 2012. The Empire State Building's total spire height of 1,454 feet (443 m) remained unsurpassed until 2013, when One World Trade Center's antenna was installed.
On June 2, 2012, a fire broke out on the 89th floor of the tower, but was extinguished by New York City firefighters before causing any injuries or serious structural damage. However, firefighting efforts were delayed because the tower's emergency standpipes were found to be dry. On June 14, 2012, President Barack Obama visited the construction site and signed a steel beam that would be hoisted to the top of the tower. Obama wrote, "We remember, we rebuild, we come back stronger!"