Joel Meyerowitz never intended to spend nine months at Ground Zero. He’d gone to the site five days after 9/11, and was doing what came naturally – raising his camera to his eye – when a policewoman’s fist descended on his shoulder. “She said, ‘No pictures, buddy, this is a crime scene,’” Meyerowitz says. “And immediately, I had this feeling that if there were no pictures being made, there would be no history. I thought, they can’t do that, it’s not right.”

The policewoman’s blow infused Meyerowitz with a sense of mission. The celebrated photographer went to the Museum of the City of New York and proposed a joint project: under the museum’s sponsorship he’d create a public, not-for-profit archive of the site. Armed with an official letter, he went back to Ground Zero and became the only photographer to have full access during rescue and clean-up operations.

Meyerowitz’s book, Aftermath, has just been published by Phaidon. A weighty volume in every sense, it contains 400 images taken over the course of a year, as the site went from a hellscape of twisted steel and rubble to an empty plot of land. Shot on a large-format camera, the images are breathtaking in their scale and detail. They capture the vastness and depth of “the pile,” as cleanup workers dubbed it.

“The first thing that hit me was the awesome scale of destruction and the power of the site,” Meyerowitz recalls, speaking by telephone from his home on Cape Cod. “It was incredibly wrenching to be in there and to see this amazing pile of wreckage stretched over 16 acres. It just seemed unfathomable.”

Famous for his luminous pictures of Cape Cod and intimate portraits of redheads, Meyerowitz found himself working in a completely different way at Ground Zero. “This wasn’t about making art—it was about collecting the evidence so that someone down the road could understand what had happened here,” he says.

The work was both physically and financially punishing. “Sometimes you witness something, you get the jitters in your stomach, and you go cold,” Meyerowitz says. “That was happening on a daily basis.” Meanwhile, he found himself getting drawn deeper into debt when the museum – deep in debt itself – couldn’t support the project. After taking out various loans, he sold his beloved apartment in Greenwich Village. “That was hard, but you move on,” he says, adding ruefully, “Not-for-profit wasn’t supposed to mean going broke.”

To add insult to injury, Meyerowitz kept getting thrown off the site and having to renegotiate his access. “The mayor’s office had banned all photography, and the firemen and police were being somewhat over-protective because of their losses,” he says. In an absurd twist, he adds, “They all had their own digital cameras and were sneaking shots.”

Eventually, Meyerowitz made friends among the recovery workers, and Aftermath includes some moving portraits of them. One portrait shows Eddie, a tough ex-con who got a job servicing machines at the site. Meyerowitz remembers him as “tenderhearted, bright and quick-witted,” and says that when the portrait was printed in The New Yorker, Eddie enveloped him in a bear hug. “Joel, I’m a made man! Even my mutha loves me now!” he cried.

Despite its subject matter, Aftermath reflects Meyerowitz’s generally optimistic nature – a trait he puts down to his upbringing in the Bronx. His parents were poor Jewish immigrants who taught their son to appreciate the wonder in everyday life. Later, when he went to art school, Meyerowitz found himself making art in the heyday of abstract expressionism, when Jackson Pollock and Willem de Kooning were the reigning kings of the art world. “It was very seductive – you could shout and jump on the canvas, you were free to do anything,” he remembers.

Photography beckoned several years later, when, as a drudge at an advertising agency, he was asked to oversee a photographer on a campaign shoot. The photographer floated around his models with the grace of a ballet dancer, and his fluidity excited Meyerowitz so much that Meyerowitz rushed back to his office and quit his job on the spot. Later he found out the name of the photographer he’d been watching: it was Robert Frank.

For the next few years, Meyerowitz took photographs on the streets of New York, falling in with another photographer who roamed the streets: Garry Winogrand. “I liked his company, and he liked mine,” Meyerowitz says. The two would stroll down Fifth Avenue, taking pictures of the colorful characters and lives bustling around them. “Walking the streets and being alive to possibilities – those were some of the most wonderful moments of my life,” says Meyerowitz.

These days, Meyerowitz is known more for his elegant, elegiac landscape photography. His 1978 book on Cape Cod, Cape Light, is recognized as one the first great color art photography books. But Meyerowitz doesn’t draw a big distinction between his landscape photography and his work in Aftermath. In both, he says, his job is to create visually compelling images by connecting emotionally to the subject matter.

Some of his most poignant images in Aftermath are of volunteers painstakingly raking the ground for the remains of individuals. Meyerowitz says that for him, this was the spiritual core of the project. “People came there as volunteers to help recover the dead, and whenever there was a find, an honor guard would come and take the remains and put them in a flag-draped basket,” he recalls. “There was a degree of spirituality that rose up from the site in an incredibly beautiful way. I think that the search for each individual was a defining moment – it was the American credo at its best.”