"It was a public-safety concern," Nate said. "Sixteen-foot-high letters that weigh 3,000 pounds, if they're not stable, it's not a good condition."
The other letters, which are "stable for the near term," will be removed later, she said.
The rumble of a helicopter over Center City interrupted an otherwise quiet Sunday morning. Pedestrians halting their morning exercises and errands looked skyward as the first P was lifted off the building at 9:30 a.m. amid cloudy conditions.
"That's sad," said Sarah Campion, who stopped to watch while out for a morning walk. "Just because it's iconic for the skyline in Philly."
Campion and others shielded their eyes as the helicopter carried letters over City Hall, kicking up dust and debris from the Dilworth Plaza construction site. The letters were lowered to the ground at 15th Street and JFK Boulevard, where crews strapped them to a truck bed. They were taken to a storage facility, Nate said.
Just three of the 12 letters had been lifted off the building by 1 p.m., clearing only the south-facing side of the four-sided alphabetic display.
"The letters turned out to be even more fragile than we had previously anticipated," Nate said. "And they decided to halt the process at that point."
Rescheduling the removal will require approval from the city and the Federal Aviation Administration. Nate said no date had been set.
Although the building recently changed owners, it was Wells Fargo's decision to remove the letters. The Philadelphia Historical Commission did not object, since the work posed no threat to the 17-ton Founder's Bell and belfry crown, said Jonathan E. Farnham, executive director of the Philadelphia Historical Commission.
The bell dates to 1932, when the Wanamaker family built the high-rise, Nate said.
ion Partners of New York, the new owner of the building, has talked of displaying one of the letters in the lobby, Nate said. But that will depend on the condition of the letters, which appeared rusted and battered as they were lowered to the ground.
Several onlookers who paused to watch Sunday expressed sadness over the disappearance of PNB from the city skyline.
"It's one of those icons hidden in plain view," said Cliff Schwinger of Cheltenham, who biked to Center City to watch the removal. "Not that it's beautiful, but it's part of the fabric of the city.