A pair of 26-foot steel beams hoisted high above the streets of Lower Manhattan about 2 p.m. Monday pushed the new skyscraper to 1,271 feet tall — higher than the Empire State Building's observation deck, Port Authority officials said.
The landmark Art Deco skyscraper's highest floor stands at 1,250 feet. With its radio antenna, it stretches to 1,454 feet.
"Today marks a milestone for One World Trade Center as the building becomes New York City's tallest skyscraper, reclaiming its place in the skyline and showing to the world the resilience of the people of our state and nation," Governor Andrew Cuomo said in a statement.
"With today's achievement, we pause to recall the heinous acts of terrorism that brought down the twin towers and claimed the lives of thousands of Americans, and we also honor the extraordinary courage of our first responders."
One World Trade Center, made out of 37,000 tons of steel and 190,000 cubic yards of concrete, will continue rising over the next several months and will ultimately stand a symbolic 1,776 feet tall, including its broadcasting antenna.
When it reaches that height, it will be the tallest building in the US and the third tallest in the world, according to the Associated Press.
Port Authority Executive Director Pat Foye said that the building, rising next to the footprints of the World Trade Center towers that were destroyed in 9/11, "will be the safest and most secure in the world."
"It will anchor Lower Manhattan and its rebirth for many generations to come," he said during a press conference announcing the tower's new height.
Construction began on the tower in 2006 and it is scheduled to open as soon as early 2014, with tenants including Conde Nast.
The David M. Childs-designed structure will boast 2.6 million square feet when it is completed.
It will have 69 floors of office space and boast two restaurants and two floors for television broadcast, topped out by a 408-foot antenna.
And the building will incorporate a host of green technologies, including reusing rain water and incorporating recycled construction materials, according to the building's website.