Reactions to the book, via e-mail and letter, phone call and anecdote, have been heartening and overwhelming.

My friend Bobbi Baker Burrows, of Life magazine, was reading the book on the train. Within no time the four or five people near her in the bar car, noticing the jacket photo, wanted to share their experiences about September 11. Photographer Jeff Mermelstein phoned to say he'd heard about my book from novelist Jonathan Safran Foer, who approached him in his local grocery store, in Brooklyn, to say that he was reading the book and to ask if Jeff knew about it. (Jeff's mentioned it in, having taken truly remarkable images on September 11, many of which were exhibited at the International Center of Photography in 2002.) Luc Sante, the Bard College cultural savant and photography historian wrote to say: "It's gripping, profound, far-reaching -- in fact, an entirely new way of writing about history, a stunning achievement."

George Rider, the de facto mayor, good-will ambassador, and resident dynamo of Lonelyvile, Fire Island (our good friend and landlord for a decade now; a budding memoirist, having published numerous columns in the local press) left me a note that was part thank-you, part journal entry: "the book...must be on the required reading list for all high school juniors and seniors. It is also a 'must read' for all of us who love our country as much as he does." He goes on, relating a story from early August: "Here I sit glued to the T.V. watching and listening to the [foiled] al-Qaeda airlines plot. It is surreal to be emersed in David's book and at the same time view the events rapidly unfolding in England. I challenge those who would perpetrate such evil to read the book and take from it the lessons to be learned. Stop! Think! Love your families, love your children, and help make a better world for all of us." Would that it were that simple.

And Richard Pyle, of the Associated Press (Saigon bureau chief during a good stretch of the Vietnam War), was moved to send an e-mail, relating several memories, written on September 11, after he watched that day's events from his Brooklyn rooftop: "There was no substitute for seeing this with one's own eyes. It was far more than visual. There was an acrid smell from the smoke, which the wind was carrying directly above us. Thousands of pieces of paper drifted with it, like a huge school of silver fish in the bright sun, falling on trees, buildings and streets."

Everyone seems to have a 9/11 story to tell, a gripping or heartbreaking or even mundane account that transports the storyteller and the listener back in time, five years, in the span of a mere paragraph or two. On September 11, each of our individual stories was part of the larger narrative.

In every facet of existence, in fact, we are all part of the larger narrative, our stories intertwined.

Spoke with Nikki Stern this morning. She had lost her husband, geologist and business analyst James Potorti, on 9/11, and had worked tirelessly with an advocacy group called Families of September 11. One of her causes was to try to ensure that news organizations provide some sort of warning before airing graphic footage of the attacks, as a way of softening the blow of such imagery for the unsuspecting viewer.

Now, it turns out, Stern has evolved into quite a writer. Over the past year, she had e-mailed me some of her unpublished social commentary. I knew that she had long ago received a master's degree in political science and had spent many years in public relations. But this weekend she had her first piece in The New York Times -- a frank, eye-opening account of a post-9/11 affair that she had had with a married man. It makes for engaging reading and reminds us that the deeper story of the effects of 9/11 on individual lives rarely conforms to a pat narrative. Instead, there are unexpected complications, pain, and revelation at every turn.

For much of the last week, BagNewsNotes has had a lively discussion about a particularly arresting photo from the book. The picture shows a pregnant woman, Isabel Daser, standing in the street on September 11, having asked a coworker to take her picture in front of the stricken World Trade Center, not realizing that a terrorist attack is under way. Daser, an architect and amateur pilot, appears with a quixotic Mona Lisa expression, as if uncertain what mood to convey for the camera.

As she explained to me: "I [had flown] around 'the twins' myself in a Cessna several times before. So I asked my colleague to take this picture. You can tell by my face that I didn't want to smile, as you normally do in pictures. I know that many hobby pilots take pictures while being on the commands at the same time. So I could imagine one 'tourist pilot' having an accident. We didn't know the truth yet." (When her daughter was born, three weeks later, Daser named her Amelia, after the pioneering aviator Amelia Earhart.)

The image, in fact, is one of many from September 11 that contain a quiet promise that the cycle of life is destined to go on, even as terror takes its mortal toll. In a similar vein, photographer Alex Webb would comment about a photograph he took that day on a Brooklyn rooftop, showing a mother and child overshadowed by a doomed and smoking cityscape in the distance. Pictures like these -- focusing on observors surviving, not on the object of their anguish -- capture "a kind of incongruity," says Webb, "which I often feel exists in situations of strife and which is often ignored: life continues in the face of disaster...despite the horrors we inflict on one antoher. [The pictures] also provide some questions: What kind of world is this child being born into? What does the future hold?"

In keeping with the theme of the book, I'd like to draw attention to several exhibitions and events next week in the New York area.

SEPTEMBER 6: At 6:30 p.m., the New York City Fire Museum will hold its opening reception for photographer Joe McNally's outsize and overwhelming "Faces of Ground Zero" exhibit, showcasing large-than-life Polaroids of people affected by the events of 9/11. Joe's work is described at length in the book.

SEPTEMBER 7: Bolivar Arellano Gallery, downtown, will display "WTC Ground Zero Photos," on view through September 24. Bolivar, shooting for the New York Post on September 11, 2001, was under Tower Two when it descended upon him, barely escaping with his life. In Watching the World Change, he describes his reactions to working near freelance photographer Bill Biggart, who lost his life in the collapse of Tower One.

SEPTEMBER 8: A memorial Mass will be held at 7:30 p.m. at St. John the Baptist Church in Yonkers, New York, by Father Gerard Critch (who appears in the book), featuring the music of the Heavenly Lullabies project, organized by Dr. Kathy Reilly Fallon, with proceeds going to children affected by Hurricane Katrina.

SEPTEMBER 11: St. Paul's Chapel (Broadway at Fulton) and Trinity Church (Broadway at Wall Street), steps from the site of the attacks, will hold an all-day rememberance, "One World...One Hope," beginning with an interfaith ceremony and ringing of the bells at 8:35 a.m. in the St. Paul's churchyard.

Among the photo shows already up around town include images posted on the fence outside Ground Zero by the World Trade Center Memorial Museum, in consort with the new Tribute Center, 120 Liberty Street. Many of the images come from the Herculean photographic project, "here is new york: a democracy of photographs," organized in the weeks after September 11 by Alice Rose George, Gilles Peress, Michael Shulan (now helping to establish the curatorial direction of the eventual memorial museum), and Charles Traub. Their efforts are explored at length in Watching the World Change. Also getting a lot of attention is "Elegy in the Dust: September 11th and the Chelsea Jeans Memorial," a real-world diorama -- clothing, shelves, dust, ashes, and all -- showing the devastated downtown storefront, intact, at the New-York Historical Society, 170 Central Park West.

Watching the World Change is about the meaning behind the images we all shared during one week: September 11-17, 2001. It is also, more broadly, about the role of media at the turn of the millennium. As such, the book seems to demand a more interactive companion. This Web site, then, is a receptacle for information about the book, a forum about the intersection of image and culture, a journal detailing my experiences and encounters, and a platform for dialogue between author and reader.

I'm finding that no matter where I go, the same thing happens whenever I mention the book, even in passing. Friends, colleagues, complete strangers -- everyone stops what they're doing and feels compelled to tell me their September 11 story. They can go on for about 20 minutes, without a break, reliving those moments again. And without exception, each tale is insightful and heart-wrenching in its own way.

This urge to recount -- and connect -- underscores not only the universality and significance of the events of that day, but also reinforces the fact that each of us feels a part of the larger narrative. Our individual, intimate experiences of horror, grief, anger, mourning, of courage or sacrifice or revelation, actually matter in the scheme of things. They are weaved into the fabric of history. They deserve to be shared.

Given my full schedule as the book is published and given the sheer number of letters, inquiries, and e-mails (to dfriend@davidfriend.net) that I've received, I will need to be selective in what I post. Please forgive me for that. And please keep in mind that the Internet (not to mention the subject of 9/11) has a tendency to invite chatter that is inappropriate for any number of reasons. Therefore, my asking for e-mails, instead of allowing automatic posts, is also a filtering mechanism.

In any case, thanks for visiting here. Come back from time to time. And please tell your friends.