Laura Bush's office called Mayor Michael Bloomberg. Mrs. Bush and her twin

daughters might be swinging through New York on a personal trip that day. The

front page of every major newspaper in the city was plastered with headlines

about possible terrorist threats against the Citigroup Center tower and the New

York Stock Exchange, and the First Lady's office wanted to know how Mr.

Bloomberg would feel about an impromptu public appearance with the three Bush

women at one of the targeted buildings.

The Mayor suggested the Citigroup tower in midtown as the

location for a photo op. About two hours later, the White House called back to

confirm that Ms. Bush and her daughters would indeed be available, which

prompted Mr. Bloomberg to quickly cancel his afternoon meetings at City Hall.

That afternoon, joined by Governor George Pataki, a few hundred Citigroup

employees on their lunch hour and dozens of TV news crews, Mr. Bloomberg and

Mrs. Bush together reassured New Yorkers that there was nothing to be afraid

of. If Laura Bush and her daughters are there, it must be safe.

This is the work of counterterrorism in the eyes of New Yorkers.

What's happening behind closed doors at the Pentagon, the C.I.A. and the White

House is above our security clearance. And the complex engineering and

construction work required to secure

buildings like the Citigroup tower against terrorist attack is beyond our

layman's understanding. But Laura Bush sitting in the atrium of the Citigroup

Center, joined by Mayor Bloomberg and Governor Pataki-especially in the weeks

leading up to the Republican National Convention-as armed gunmen trawl

Manhattan's streets, is something that we all can understand.

New Yorkers don't seem to mind. After all, as they approach the

third anniversary of 9/11, cranky, temperamental city dwellers seem to have

developed a new psychic balance between nonchalance about the potential risks

of attack and a growing expectation that security precautions will necessarily

hamper their day-to-day lives. If those white-collared suits showed up at

Citigroup one morning and didn't have

to hand over their briefcases for inspection, then they'd be upset. Despite hours-long delays and missed

appointments, city grunts from truck drivers to tax accountants welcomed the

recent warnings. The mantra "Better safe than sorry" came up at least once in

most interviews on local television newscasts.

Mr. Bloomberg's press secretary, Ed Skyler, understood the

symbolism all too well, calling the visit "an incredibly strong show of

solidarity with New Yorkers to appear at a place that is on the cover of every

newspaper as a target of choice for terrorists."

And perhaps it was, despite the fact that Homeland Security

Secretary Tom Ridge would later confirm that his Aug. 1 warning about the

terrorist threats stemmed from intelligence that was mostly several years old,

and that there was no real indication that any attack was imminent. At the same

time, however, Mrs. Bush's husband is also running for re-election as a wartime

President, and the image of a vigilant, responsive and sympathetic First Family

certainly wasn't one that the White House was shy about projecting.

Perhaps to reassert the administration's emphasis on security,

Mr. Ridge came to the Citigroup tower the next day to give his own press

conference, in which he denied that election-year politics had anything to do

with the timing of his agency's terrorism-intelligence disclosure.

"We don't do politics at the Department of Homeland Security,"

Mr. Ridge said.

The remark drew a few snickers across the room, perhaps because

Mr. Ridge came under criticism a few weeks ago for announcing an extremely

vague warning of a possible terrorist attack around the same time that the

nation's eyes were turned to Senator John Kerry's choice of a Presidential

running mate.

"One cannot help but have somewhat of a healthy dose of cynicism

with all these terrorism announcements in the last six weeks," said Jerry

Hauer, former director of the Office of Emergency Management. However, he said,

the specificity of Mr. Ridge's most recent warning-with videotapes and

documents pointing at specific targets-warranted his making the announcement.

"Even if you maintain that cynicism and are skeptical about what's going on

with all these threat warnings, you can't ignore this confluence of

information, and that was the very important message in what Secretary Ridge

came out with."

The city fathers can't afford to miss that message. They remember

when the city's hotel, restaurant and entertainment industries suffered badly from

a drastic drop-off in tourism dollars.

Cristyne Nicholas, the president of the city's tourism bureau,

NYC & Co., learned about the terror alerts by watching the news. By 8 a.m.

the next morning, she was in her office and made her first call to the Nasdaq

market site in Times Square-to make sure that everything was running smoothly

at the financial-services market. She next reached out to NYC & Co.'s

chairman, Jonathan Tisch, who recommended that the staff stage an evacuation

drill. A bit of humor ensued when the staff, some 70-strong and led by Ms.

Nicholas with a bullhorn, emptied out onto the corner of 53rd Street and

Broadway-the very spot where a huge queue of people were lining up to gain

admittance to the David Letterman show.

Amid the confusion, Ms. Nicholas raised her bullhorn and shouted,

"NYC & Co., good job-class dismissed." Then, ever the tourist cheerleader,

Ms. Nicholas said to the Letterman fans, "To all of you on line, thank you for

your visit to New York. We appreciate your coming to Manhattan."

Ms. Nicholas later sent out a memo changing the staff's

evacuation-drill location.

"I was afraid I might get a fine for using a bullhorn without a

license," she said.

The tourism chief then put out a statement-"New York is open for

business!"-and instructed her department heads to dial up contacts at companies

around the city and informally survey them for any drop-off in their business.

Ms. Nicholas said that few, if any, reported any cancellations.

Charles Gargano, the head of the state's economic development

corporation, said he got word on Friday, July 30, that a major terrorism

announcement was imminent, but didn't get the details until watching Mr. Ridge

on the news. He said his first act was to gather several of his senior

executives and have them reach out to the heads of security at many of the

city's major corporations, to assure them that the ESDC could act as a liaison

between the private sector and law-enforcement authorities.

The next day, he joined Mayor Bloomberg at the Citigroup tower to

escort the three Bush women in their public-relations exercise, first through

the building's cafeteria, and then through other public areas.

"We went around telling people, 'You're safe. You can count on

law enforcement,'" he said. "They were all saying they were coming to work. A

lot of courage was shown, a lot of backbone. That for me was a very telling

experience."

It's a pantomime-from antiquated threat, to the Homeland Security

and White House response, to the renewed opportunity to the city fathers to get

their message across-that New York can expect to see happen again and again, it

seems, for a long time. At City Hall and at the Bush White House, it's good for

business.

Mr. Ridge's most recent alert listed five possible terrorist

targets: the NYSE, the Citigroup tower, the Prudential building in Newark,

along with the headquarters of the International Monetary Fund and the World

Bank in Washington. Those targets were identified through computer equipment

and documents seized in Pakistan last month.

Of the five, the 59-story, 1.6 million-square-foot Citigroup

building is perhaps the easiest to imagine as a target; not only is it one of

Manhattan's few iconic skyscrapers-like the former World Trade Center complex,

but its four stilt-like legs give the building the appearance of vulnerability

to attack from a ground-level bomb.

But long before Mr. Ridge's warning-in fact, long before Mr.

Ridge was the head of Homeland Security, before there was a Department of

Homeland Security, the building's owner, Boston Properties, anticipated that

specific vulnerability. In August of 2002, the owners began construction to

reinforce the odd leg that stands apart from the others and the surrounding

area with extra metal shielding that would act as a bomb shield, reported The New York Times .

While that may have been a prudent move, the building's original

structural engineer, William LeMessurier, said that he believed the tower would

remain standing even if that leg were to be somehow destroyed.

"The whole [steel skeleton] is highly redundant," Mr. LeMessurier

said, "meaning there are many paths for forces to go. Taking out one column

would not, in my opinion, cause it to collapse."

In addition, Mr. LeMessurier pointed out the building's weight is

not only distributed over four legs. Its central core, which runs straight up

the building, supports about half of the building's weight. And that core, like

the other three legs, is inaccessible to a vehicular-borne bomb. And it would

seem to be nearly impossible for a single individual to smuggle enough

explosives into the building to actually bring it down.

During his phone interview with The Observer , the 78-year-old Mr. LeMessurier said that he was

wearing the bronze belt buckle given to him by the building's steel contractors

at the building's "topping out" party in 1976. The retired structural engineer,

who also designed the endoskeleton of the Federal Reserve building in New York,

said that despite his estimation of the building's strength, he didn't design

the structure with an eye toward guarding against terrorism.

"The idea of all these potential attacks never got into anybody's

head until the World Trade Center collapse."

Well, not exactly. In the 1980's, Citigroup hired a leading

building-demolition company, Controlled Demolition Inc., to perform a

vulnerability assessment on its tower. According to the company's president,

Mark Lowizeaux, Citigroup was indeed worried about terrorism; not Islamic, but

American.

"This was back when financial institutions were foreclosing on

farms," said Mr. Lowizeaux, "and there were a lot of farmers driving into

reflecting pools in D.C."

Mr. Lowizeaux said a confidentiality agreement prevented him from

talking about the results of his company's assessment, but he did say that the

suggestions he made, which he believes the company implemented, involved

beefing up the security of the building, in addition to strengthening up the

tower physically.

And although Mr. Lowizeaux took pains to stress that he thinks

the Citigroup tower is a "marvelous" structure, designed by a top-notch

architect and construction company, his experience in the demolition business

teaches him that no building is impregnable.

"Just as there is no natural feature on Earth that can withstand

man and his ingenuity, there is no manmade structure that could withstand man

and his ingenuity, assuming access," he said.

Stephen DeSimone, a structural engineer who has helped design

many of the country's tallest buildings, and who is a member of the Urban

Habitat's High Rise Building Task Force, drove that point home.

"You identify the most probable threat-is it a car bomb, a truck

bomb?-and then at that point, through a series of modeling situations, you try

to identify the vulnerabilities of the building and take protective design

measures to prevent significant structural failure," he said. "But you cannot

design for everything."

On Aug. 2, a day when scores of machine-gun-toting policemen

stood poised throughout the building, there still appeared to be room to drive

a small vehicle between the concrete barricades at the corner of Lexington and

53rd Street, and pull up to the leg that stands flush to the sidewalk on 53rd

Street.