Flying the presidential jet over lower Manhattan for a photo op, sending panicked New Yorkers running into the streets, was as "stupid a thing to do as one could dream up," the White House said Wednesday. And it cost far more than the $328,835 the Air Force says it spent.

New York Mayor Mike Bloomberg's office said it doesn't have hard numbers yet on how much the city had to spend to deal with the panic caused when a backup jet to Air Force One, accompanied by two F-16 fighter jets, flew around for approximately 30 minutes for a photo shoot commissioned by the White House Military Office.

The city's 911 operators were inundated with phone calls as residents of New York and New Jersey looked out their windows to see a jumbo jet and two fighters circling lower Manhattan, where nearly 3,000 people were killed in the Sept. 11, 2001, terror attacks.

The New York Police Department said there were an estimated 97 calls to 911 about the flyover in a one-hour span. That is an increase of about 15 percent from a typical hour.

Across New York Harbor, ambulances and police officers in Jersey City, N.J., were deployed to Exchange Plaza after the city received 13 emergency calls requesting information or medical assistance, said city spokeswoman Jennifer Morrill.

"(The police) had a loudspeaker, telling people it wasn't an attack," she said. "There were people falling down stairs, and there was a lot of confusion and chaos."

"We don't have any inventory nor will we be able to prepare one," Jason Post, a spokesman for Bloomberg, said when asked to give the cost of the emergency response.

"We can't count the jet fuel like the Pentagon did. It was an unwelcome disruption, but we don't have a number to put on it."

The cost extended beyond municipal government to lost hours for New York and New Jersey businesses, as workers streamed out of their offices in panic.

In lower Manhattan a number of companies ordered their employees to evacuate after seeing the Air Force One backup plane fly past their high-rise windows.

In the World Financial Center complex alone, at least two of the four towers, representing some 20,000 office workers, were partially evacuated, said Melissa Copley, a spokeswoman for Brookfield Properties, which manages the buildings.

"It's kind of hard to say. There were two (companies) in one building, three in another," she said. "I'd say less than half the workers in those buildings evacuated."

The 911 tapes released on Wednesday vividly revealed the extent of the disturbance.

"We just saw a big airliner being escorted by two fighter planes next to it," one caller told a 911 operator. "We just saw a jetliner fly low-ceiling above the medical center. We thought it was gonna crash into us. There were two fighter planes next to it." 

The lack of a public warning on the flyover prompted outrage from both Bloomberg and President Obama, who both said they were unaware of the photo-op.

"It was a mistake, as was stated. It was something we found out about along with all of you. And it will not happen again," the president said.

White House spokesman Robert Gibbs elaborated on the president's words on Wednesday, calling the flyover as "stupid a thing to do as one could dream up."

If President Obama had had "any knowledge of the stupid idea to go take pictures of the plane in New York, I can assure you that wouldn't have happened," Gibbs said aboard Air Force One.

In an interview with MSNBC later in the day, Gibbs said, "This was a dumb idea on just about every level that you want to analyze it on. I would certainly agree with that. The president would agree with that. 

"He was furious when we told him about it and he's asked that the deputy chief of staff look into how a decision like this got made and to ensure that it never happens again. And that's what we're doing right now."

It may be the one issue on which Gibbs and Sen. Kit Bond, R-Mo., agree.

Calling it a "glamour shot," Bond said the "stunt is a symbol of how far from their minds the attacks of Sept. 11 are."

White House Military Officer Louis Caldera has taken the blame for authorizing the flyover, and he has apologized to the public.

The Air Force said the three-hour mission to New York was considered part of its training schedule and would have been flown regardless of the photo-op.

Of the $328,835 spent, about $35,000 was the cost of fuel, with the remainder spread over regular repair and maintenance costs estimated over the life of the aircraft.

Only crew were on board the flight, Air Force spokesman Vince King said.

Stephen Clark contributed to this story.