The nation's largest city is struggling to cope with the loss of life and a feeling of vulnerability in the wake of its biggest catastrophe - two hijacked planes crashing into the World Trade Center.
The assault has thrust New York, tragically, into the position of becoming the premier test case for how a city responds - psychologically and practically - to a massive terrorist attack.
While other cities around the world - Munich in 1972, or Jerusalem on most days of the week - have been forced to deal with the aftermath terrorist incidents, none approach the scale of what New York is now going through.
The tragedy is forcing the city to confront everything from a shortage of blood supplies at hospitals to the need to calm a panicked public. Calls have gone out for additional medical help and psychological counseling. The National Guard has been summoned to try to help.
"The only thing we can do now is remain calm and focus on the rescue efforts ... and pray," Mayor Giuliani said, his voice uncharacteristically shaky in an interview with a local television station.
Almost immediately after the first plane hit the World Trade Center, New York totally shut down. The George Washington Bridge, the Lincoln Tunnel, and all entrances and exits to New York were closed down, as were all railroads. The New York City subway system, which handles 4.3 million people per day, also stopped running.
The city was prepared, as best it could be. As a result of the 1993 bombing attack on the World Trade Center that killed six people, New York planned for a massive terrorist attack. It built a $13 million emergency center that was designed to coordinate the city's response to severe storms, terrorist attacks, and everything in between. The center opened in 1999 - on the 23rd floor in one of the smaller buildings of the World Trade Center complex. The center was compromised as a result of this attack, but as of this writing, the extent of the damage was not known.
While it was ridiculed by critics when it opened as "Giuliani's bunker," the planning did allow the city to effectively coordinate its emergency response. Nonetheless, within minutes after the attack, the lower end of Manhattan quickly disintegrated into what appeared like a war zone.
"This is a siege mentality," said a policeman, urging people to stay calm and away from downtown.
In a sign that it will take New York some time to return to something close to normal, people became concerned when they saw airplanes in the sky. "Why is there a plane above us?" asked Amy Phillips, who works at Rockefeller Center. "I keep thinking of all the addresses that we have of all of our clients who have the World Trade Center addresses.... You know, they are just gone," she said as tears ran down her cheeks.
Jane Brown, visiting from South Carolina, was staying a few blocks from the Trade Center. "It sounded like someone dropped hundreds of tons, like a giant truck fell on the street.... We could barely see the tower because there was so much smoke."
Elizabeth Armstrong contributed to this story.