Hours later, a second man made his own ascent up the building - a stunt that drew the attention of hundreds of onlookers, along with TV cameras that captured the drama in real-time. Crowds on the street pressed against police barricades to watch the climb, and people clapped and cheered for him while snapping pictures on their cell phones.
He, too, was taken into custody as he reached the top.
"Only in New York. This is why I live in New York," said 29-year-old Emily Perschetz, who watched the second climber for about 20 minutes.
"You've gotta respect them for trying," she added.
At moments during his ascent, the second climber appeared to slow and tire, and officers awaiting him shouted encouragements from the rooftop and even dangled a rope, which he did not take, police said.
Officers at the scene became concerned that the man might be an emotionally disturbed copycat, and he was taken to a hospital for a psychiatric evaluation, according to police, who identified him as 32-year-old Renaldo Clarke, of Brooklyn. There was no working phone number listed under his name and address.
The building's facade is covered with slats that allowed the men to climb the tower like a ladder.
Robert pumped his fist as he made it to the top, where police took him into custody. The 45-year-old was facing charges of reckless endangerment, criminal trespass and disorderly conduct, police said.
Robert's Web site says he has climbed more than 70 skyscrapers around the world. He was arrested in February after climbing a 42-floor building in Sao Paolo, Brazil.
The stunts were staged at the Renzo Piano-designed Times building, just a block south of the busy intersection at Eighth Avenue and 42nd Street, across the street from the Port Authority bus terminal.
A spokeswoman for the Times, Catherine Mathis, criticized the climbers, saying the newspaper was "taking steps to prevent future occurrences."
"Their illegal and ill-considered actions jeopardized their safety and the safety of others," Mathis said in a statement.
Earlier, she said that no one at the newspaper knew of Robert's plan in advance.
The Times itself has "a very green building," Mathis noted.
"We wanted to minimize our environmental footprint." She said the ceramic slats save energy by reducing the amount of heat and light entering the building, where the Times moved last year.
Robert said in a news release he was climbing to mark World Environment Day and "to create support for far greater and urgent action from world leaders on global warming."
His Web site says he climbs even though he suffers from vertigo and is "60 percent disabled" from previous accidents. It also says he has been jailed many times but it does not matter because he "would rather stay in a prison than in a hospital."
The second climber wore a T-shirt with the words "Malaria No More," the name of an organization which promotes awareness about malaria and raises money for bed nets. Martin Edlund, a spokesman for the organization, said the climber was not affiliated with the group.
Clarke's Facebook page says he enjoys climbing and lists "xtreme living" among his interests. The page identifies him as an information technology support manager for a Manhattan advertising agency, and it says he is pursuing an undergraduate degree in physics. He did not immediately return an online message.
One city councilman is hoping that at least one of the climbers gets to know what the inside of a New York City jail looks like.
"Regardless of the cause, in this day and age the police department has more important things to worry about than ridiculous stunts like this that endanger the police and public," Councilman Peter Vallone Jr. said after Robert's climb. "If he wants to climb something, he can climb the walls inside his jail cell at Rikers."
Shaznay Jones was more amused than Vallone as she watched the second climb while smoking a cigarette.
"It looks crazy, like he's on drugs, like he's on something," Jones said. "I never saw anything like this before."
New York's skyscrapers have long attracted high-rise stunts.
The host of a cable TV show called "Stunt Junkies" was arrested in 2006 as he tried to parachute from an Empire State Building observation deck. Police and security guards seized him and handcuffed him to the 86th-floor security fence as he climbed over it.
And in 1974, French artist Philippe Petit made a daring and illegal wire-walk between the twin towers of the World Trade Center. British director James Marsh made "Man on Wire," a retelling of the derring-do.