New York ? From a day that held nothing but chaos, confusion and fear of the unknown has sprung an annual day of remembrance that is just the opposite – measured, orderly and achingly familiar.

Today, four years to the day since terrorists transformed U.S. jetliners into deadly missiles that toppled the World Trade Center and killed 2,749 people, the city will pause for a memorial ceremony that mirrors almost exactly all the anniversary ceremonies that have come before it. Bagpipes will wail, bells will toll, family members will speak of lives cut short, the names of each person killed will be read and four moments of silence will be observed in remembrance of each awful event of that morning – the moment each tower was struck, the moment each tower fell.

“Time will never dull the grief of those who lost their loved ones on that tragic day, nor will it diminish our dedication to remembering our heroes and ensuring that a fitting memorial rises in their name,” New York Gov. George Pataki said of Sunday’s anniversary.

Yet for all the constancy of the annual ground zero ceremony, much has changed since Americans somberly gathered at that still-gaping hole here just one year ago.

Development of the World Trade Center site is moving decisively forward, despite continued controversy about land that many families consider sacred ground. A Zogby International poll shows that although the majority of Americans still consider 9-11 to be the most significant event of their lifetimes, a full 29 percent admit to rarely thinking about that day anymore.

And Hurricane Katrina has pummeled the Gulf Coast, reaping a scale of physical destruction unsurpassed in recent American history and a death toll that some have said could reach 10,000, drawing an outpouring of emotion and generosity comparable to that in the days after 9-11.

Craig Esposito, of Bellmore, New York, left, bearing a tattoo of his father William Esposito, who died in the 9-11 attacks, on his back, is comforted by his girlfriend Heather Broome, of New York, as they stand outside ground zero, the site where the World Trade Center once stood in New York.

Three years ago, on the first anniversary of the terror attacks, families were for the first time given the opportunity to walk in the space occupied by the fallen towers where their loved ones died, and grief was the prevailing emotion of the day. But in the years since, many of those most affected by the events of 9-11 have consciously fought to turn the anniversary of that terrible morning into something more positive.

Several groups advocate making 9-11 a national day devoted to volunteerism, and such movements have begun to gain traction.

Also, several dozen New Yorkers – many of them firefighters who survived 9-11 – gathered Friday morning at a firehouse on New York’s Upper West Side. Part of a group called New York Says Thank You was there. They were about to depart for Illinois where they would spend the 9-11 anniversary weekend helping to rebuild the small community of Utica, which was hit by a tornado in April 2004. Much of the town was leveled, and eight people were killed. The group, which aims to help communities that sent aid to New York in the days after 9-11, already has vowed to spend next year’s anniversary helping to rebuild New Orleans and surrounding towns.

Still, in many ways, the truest proof of the state of the country four years later is that life, in many respects, will go on as normal today.

Most NFL teams will open their 2005 season, and the New York Giants will play on their home turf after a pregame ceremony that will involve representatives from the New York Fire and Police Departments.

The final day of the U.S. Open tennis tournament will be held in Flushing Meadows in the borough of Queens.

New Yorkers will repaint a firehouse and restore a damaged Little League diamond in a small town in Illinois.

And pumps will continue to draw water out of the devastated city of New Orleans while the dead are identified and counted.