New York's rebuilt World Trade Center, an emblem of the city's resilience and renewal after horrors of 9/11, has been triggered fears about lax security
Within the space of a fortnight, revelations of repeated security breaches at what should be one of the most tightly guarded buildings in the United States have been met with incredulity by locals.
The first breach took place at night on September 30 last year, when three base-jumpers -- one of whom worked on the site -- accessed the tower before leaping off and descending to the streets of Manhattan.
The second case, on March 16, saw a 16-year-old enthusiast slip through a fence and take an elevator to the 84th floor of the highly symbolic building.
He then made his way up to the 104th floor, sneaking past a sleeping guard, before using a ladder to reach the spire at the top of the 541-meter building.
The guard caught napping was subsequently fired. The teenager was arrested and charged with misdemeanor criminal trespass.
In the base-jumping case, four men -- the three parachutists and a lookout -- were arrested and charged this week following a five-and-a-half month investigation.
A video of the base-jumpers' daring nighttime descent appeared online this week, quickly racking up more than a million views.
One of the men arrested, 33-year-old Andrew Rossig, said breaching security at the site had required "no effort whatsoever."
"We just kind of walked in. It's supposed to be the most secure building in the world," he said.
"God forbid it was somebody else getting in there with a real intention to harm New Yorkers."
- No immunity for daredevils -
New York Police Commissioner William Bratton decried the stunt, however.
"These men violated the law and placed themselves, as well as others, in danger," he said as he announced the arrests.
"Being a thrill-seeker does not give immunity from the law."
Security for One World Trade Center, which will become the tallest building in the United States when it opens in 2015, is now shared between the Port Authority of New York and New Jersey and the Durst Organization real estate company, which manages and leases the site, Durst communications chief Jordan Barowitz told AFP.
When the base-jumpers pulled off their stunt, the Port Authority was solely in charge of security, he emphasized.
"We are in charge of the security inside the site since January. Outside, it's Port Authority," Barowitz said.
"We are very concerned and we are working with the Port Authority to improve the security of the site," he added.
He did not reveal the number of personnel deployed to guard the tower, which has already leased 55 percent of its office space ahead of the opening.
Port Authority spokesman Joseph Dunne said officials were continuing to "reassess" security practices at the site and were looking at ways of ensuring it was "as secure as possible."
"We take security and these type of infractions extremely seriously and will prosecute violators," he added.
In the aftermath of this week's revelation about the base-jumpers, two journalists from CNN tried unsuccessfully to penetrate the site last Tuesday, before being arrested.
The new World Trade Center is being erected on the site of the old Twin Towers, which was destroyed by Al-Qaeda suicide attackers on September 11, 2001, killing nearly 2,800 people.
Once completed, the complex will include a museum, a permanent outdoor memorial, five skyscrapers, a subway station, shops and an arts center.