The Port Authority of New York and New Jersey and the New York City police commissioner denounced the parachute jump off One World Trade Center last year by three skydiving enthusiasts as a lawless act that put others in danger.
"The Port Authority joins the NYPD in condemning this lawless and selfish act that clearly endangered the public," the agency said in a statement. "One of the jumpers worked construction at the WTC and violated the spirit of respect and reverence for this sacred site that almost all connected with the WTC project feel."
Four men - three daredevils and someone accused of being an accomplice - were arrested this week in connection with the September 30 "Base jumping" from America's tallest building. They were arraigned on charges including felony burglary.
"These arrests should send a message to anyone thinking about misusing a landmark this way," Police Commissioner William Bratton said. "Being a thrill-seeker does not give immunity from the law."
New York City Mayor Bill de Blasio said the city wanted to "deepen" its coordination with Port Authority police to address the situation. "It's obviously not an acceptable state of affairs but we think it's one that together that we can resolve," he said.
The arrests came days after a New Jersey teenager was accused of unlawfully entering the site, eluding an inattentive security guard and spending about two hours atop the 541.3-metre-tall tower. The skyscraper, still under construction, crowns the rebuilt World Trade Center, a project steeped in security concerns.
On Tuesday, Port Authority police arrested two CNN producers, accusing them of trying to breach security at the site. Police spokesman Joe Pentangelo said Yon Pomrenze and Connor Fieldman Boals tried to enter a gate leading into the lower Manhattan site at about 2pm, but were stopped by an officer.
He said Boals then twice tried to climb a fence near the World Trade Center PATH subway station. He said the men then tried to push their way through a gate and were arrested on criminal trespass and other charges.
A spokeswoman for CNN said the men were in the area to do a story about the recent security breaches and were not asked to sneak onto the site.
The New York Police Department said last year that investigators were looking for two parachutists in dark jumpsuits seen floating near the building around 3am on September 30, landing by a nearby skyscraper and walking away.
It was "very exhilarating," one of the accused jumpers, Andrew Rossig, said as he and co-defendant James Brady headed to a police precinct to surrender.
"It's a fair amount of free-fall time," he said. "You really get to enjoy the view of the city and see it from a different perspective."
Rossig, an avid Base jumper - an acronym that stands for "building, antenna, span, earth" - said the skydivers took care to keep from endangering anyone, choosing a time when streets would be largely deserted. Brady, an ironworker who formerly worked at the trade centre, declined to comment.
Arraigned late on Monday were Rossig, 33, from Slate Hill, New York; Brady, 32, from Kings Park, New York; Marko Markovich, 27, from Lake Ronkonkoma, New York, and Kyle Hartwell, 29, from East Patchogue, New York. They face charges of misdemeanour reckless endangerment and misdemeanour jumping from a structure in addition to felony burglary.
It wasn't immediately clear how investigators zeroed in on Rossig, Brady, skydiving instructor Markovich and Hartwell, accused of being their cohort on the ground.
It wasn't immediately clear how investigators zeroed in on them. Police searched their homes last month and got video of the jump, which hadn't been posted online or otherwise publicised, Rossig's attorney Timothy Parlatore said. But he said authorities didn't signal arrests were imminent until 16-year-old Justin Casquejo's arrest last week.
The NYPD devotes more than 200 officers, surveillance cameras and other technology to protect the perimeter of the site, while Port Authority police and private security agents guard the inside. Ultimately, plans call for a US$40 million system of barriers and checkpoints around the 6.48-hectare trade centre site.
But Rossig said the jumpers got in simply by walking through a gap in a fence, echoing an account the Port Authority says Casquejo gave police about what he did. Casquejo faces a misdemeanor trespassing charge.