Bill McCaffrey takes it all in stride.
"Something may happen, something may not," the ad agency employee said Wednesday afternoon from his barstool overlooking one of the city's potential terror targets. "You can worry about that on every street corner. It's part of living in New York."
In New York City and in the Washington, D.C., area, where people have grim experience with terror, a federal alert and a message attributed to Osama bin Laden prompted many to take disaster-preparation steps - and admit to a few jitters.
Police were wary, closing major bridges when a package seemed out of place or license plates didn't match. The public was on guard, too: New Yorkers were calling police with terror tips at nearly three times last month's rate.
Yet in both places, many people said they were unafraid and determined to go about their lives.
"I'm not changing our lifestyle," said Liz Davis, 43, of Alexandria, Va., who said she has plenty of food at home but has not taken other emergency steps. "Part of living near D.C. is living at a ground zero of sorts. It's part of the package."
Said former New York Mayor Ed Koch: "We've been through too much to be frightened."
Others greeted the warnings with a yawn. "I find people heed the snow alerts more than terror alerts," choreographer Mindy Cooper said as she walked her dog in Central Park.
As most went about their normal routines, police stepped up security.
In New York, plainclothes officers were prowling the subways. Heavily armed units known as Hercules teams were making surprise visits to likely targets, like Times Square, to disrupt terrorist reconnaissance. Hundreds of police academy graduates were moved from patrol duties in high-crime precincts to Omega posts - those at potential terror targets.
"We're up against a very cunning, patient foe and you cannot underestimate them," said Police Commissioner Ray Kelly, who traveled to Washington this week to discuss intelligence reports with federal security officials. "We're just at the beginning of a long war and we're going to be involved in it for a very, very long time."
In Washington, police asked employers to be prepared to take care of their workers and customers in the event of an attack. "Have the proper tools and equipment to be able to do it," said District of Columbia Police Chief Charles H. Ramsey.
Packages considered suspicious shut a Washington subway station and the 14th Street Bridge - a major route from Virginia less than two miles from the White House. In New York, the Whitestone Bridge between the New York City boroughs of the Bronx and Queens was shut down because a truck with mismatched plates raised concerns. Nothing threatening was found at any of the locations.
Certain adjustments were being made by the public. Although the transit authority in New York does not keep daily ridership figures, workers said crowds seemed lighter on underground and commuter rail this week.
Nearly 100 calls a day were being made to the NYPD's terror tip line - up from an average of 33 last month. And many hardware stores in New York and the Washington area have seen a rush on emergency supplies.
Federal officials have recommended Americans take basic disaster-preparation steps such as maintaining a three-day stockpile of food and water. They also recommend obtaining duct tape and plastic sheeting to seal a house in a chemical or biological attack.
"There's not a roll of duct tape to be found in this town," said Alexandria, Va., hardware store employee Tim Leonard.