Abdulrahman Zeitoun is the real-life hero of Dave Eggers's new book. In the aftermath of hurricane Katrina he paddled from house to house in a canoe, offering help to his neighbours. For his trouble, he was arrested as a suspected terrorist

Saturday afternoon and the Zeitoun household is bustling with activity, as you quickly get the impression it always is. Kathy Zeitoun, dressed in a blue silk shirt and matching hijab, is fluttering around making spiced pumpkin-flavoured coffee and answering the constantly ringing phone. Noises emanating from four of her five children bubble up like broth from the back room where they are watching Kung Fu Panda on a giant flat-screen TV. Kathy seats me in the neat and orderly living room, which is dominated by cream leather sofas and a watercolour of a street scene from her husband's native Syria. Beside it is a framed 3D model of the Qur'an.

Gradually, out of this domestic pleasure dome, telltale signs emerge of the calamity that struck the Zeitouns almost five years ago. An outside wall of the house is stained with a faint but still clearly discernible line at about shoulder height, a record etched in paint of where the flood waters settled.

"Most of the time I don't think about what happened at all," Kathy says, as she pours the coffee. "Until I step out on to the street – then it all comes back to me."

In recent days Kathy has been forced to think back a lot on the events leading up to and following 29 August 2005, when hurricane Katrina ripped through her city of New Orleans, breaching its levees and immersing much of it, including her home, in several feet of water. The reason for her current preoccupation is the publication of the new book by that one-man literary factory Dave Eggers, whose best-known previous work is the memoir A Heartbreaking Work of Staggering Genius.

The book, entitled Zeitoun, is, as its name suggests, a very personal telling of a national tragedy. It explores what happens when the entire fabric of society collapses, plunging a city into a parallel universe where there is no justice, no government, no protection, no respect. It does so exclusively through the eyes of the Zeitouns. Eggers spent three years on and off interviewing the family, then translating their memories into his trademark vivid yet restrained prose.

At the centre of the book is Kathy's husband, Abdulrahman, or Zeitoun as he is universally known, a New Orleans building contractor who has attained almost mythical status. Not only is he the dominant character in the 339 pages of Eggers's book, but in the US press he has been dubbed an "all-American hero" for the phlegmatic way he conducted himself in the midst of catastrophe.

That said, when I arrive at his house he is nowhere to be seen. He turns up an hour and a half late, which Kathy insists is wholly true to form and actually not that bad: he kept her waiting for two hours on their wedding day. He could have turned up 10 hours late and still you'd forgive him, just as soon as you felt his firm handshake and the embrace of his warm smile. "Zeitoun," he says in self-introduction, as though there were any doubt.

He comes into the room straight from a building site with his trousers splattered in mud. "I really don't feel we deserve all this attention," he says in a thick Middle-Eastern accent. "I only did what I had been brought up to do."

What he did was to stay in New Orleans when the hurricane struck, driven by a conviction that that is where he belonged. While Kathy and the kids joined the mass evacuation from the city, he hunkered down at home; and when the levees broke and the flood water poured in, he put to use a battered old canoe he owned to navigate the streets of his neighbourhood, now turned into canals.

Zeitoun paddling through New Orleans in his canoe may well become one of the enduring images of Katrina. A line drawing of him in the boat is printed on the cover of Eggers's book, and the film director Jonathan Demme plans to make an animated movie of his story next year.

Zeitoun takes us on a guided tour of the route that he negotiated in his canoe in the days after the storm. He begins by pointing to a pillar at the front of his house. "That's where I kept the canoe tied, like you'd tie up your horse."

We set off by car along the maze of streets around his neighbourhood. On every street corner he has a tale to tell. The first stop we make is at a house of grey clapboard standing on stilts. In the hurricane, the flood waters reached almost up to its windows. As he paddled by, Zeitoun explains, he heard a voice faintly crying "Help!". He swam to the front door and inside found a woman in her 70s hovering above him. In one of the most memorable phrases of the book, Eggers writes: "Her patterned dress was spread out on the surface of the water like a great floating flower."

"She was inside the house holding on to the bookshelf with water up to her shoulder," Zeitoun recalls, as we stand outside the house. "She must have been in the water for about 24 hours by then."

Zeitoun helped the woman reach safety in a fishing boat, which was no small feat given that she weighed 90kg (14st). His construction skills and great strength proved invaluable as he levered her on a ladder out to the vessel.

Our tour continues and we pass the house of a local Baptist church pastor and his wife whom the Zeitouns had known for years and who similarly cried out for help. Further on, we come to the residence of a man who was stranded and to whom Zeitoun brought food and water every day while he still had his canoe and his liberty.

All in all, Zeitoun reckons he must have helped to save or rescue more than 10 neighbours. "The way I thought of it was, anything you can do to help. God left me here for a reason. I did what I was brought up to do – to help people."

At this point, our journey begins its descent to a much darker place. Zeitoun points out the spot where he saw a human body floating in the filthy water. Then we arrive at Claiborne Avenue where the weirdness truly began. It was 6 September, six days after the hurricane, and he was in the house – his own property, which he rents out – along with a Syrian friend, Nasser Dayoob, his tenant Todd Gambino and Ronnie, a white man Zeitoun didn't know but who had asked to stay in the house for shelter. Zeitoun was on the phone to his brother in Syria when six unidentified police officers and National Guardsmen burst through the front door dressed in military fatigues and bullet-proof vests and carrying M16s and pistols. Zeitoun explained he was the landlord, but the only response was a demand from one of the National Guardsmen for his identity card.

"All he did was look at my ID," Zeitoun says, "and that was enough. Nothing else. No other questions. The moment he saw my name he said, 'Get into the boat!'"

We get back into the car and retrace the route of that boat ride, stopping at the Greyhound bus station near the city centre. Today it's back to a semblance of normality, with its familiar canine logo and silver buses lined in rows. But when Zeitoun was carted off there, he and his three companions found themselves surrounded by 80 or so men with assault rifles and dogs, a mixture of National Guardsmen, prison wardens and soldiers, some of whom had recently been serving in Iraq and who seemed to approach the situation in New Orleans with a war-zone mentality. The closest thing it reminded him of was Guantánamo.

'You guys are al-Qaida,' said one soldier. 'Taliban,' said another



He takes us to see a concrete compound at the back of the bus station and describes the network of chain-fence pens that had been erected overnight to convert the area into a makeshift detention centre. Zeitoun and his companions were flung into one such cage, with armed soldiers standing guard over them on the roof.

"Why are we here?" they asked a passing soldier. "You guys are al-Qaida," came the reply. Another soldier said as he passed: "Taliban."

It was like a dagger blow for Zeitoun, for himself personally and for his vision of America, the country where he had come to live as a young merchant seaman from Syria and which he had always believed was a land of fairness and opportunity. He had come initially in search of work, never expecting to stay, but he then met Kathy, a local Louisiana woman who had converted to Islam four years previously. They had built a life together, grown their construction business and had children. And now here he was being called a terrorist. "I felt very bad. It was very hurtful. These guys wanted revenge on us, no matter what."

He was kept penned up at the bus station for three days and nights, and interviewed by officers from homeland security who seemed to think they had caught a big fish. He says now that whenever he drives by the Greyhound station – or Camp Greyhound as it was dubbed – dark thoughts enter his mind.

What dark thoughts? "Being called those terrible names. The memory of people refusing to help. Imagine you see a doctor and you shout at him, 'Can you help me?', because your foot is infected and hurting badly, and he's wearing a green medical gown and a stethoscope around his neck, and he says, 'I'm not a doctor,' and walks on. How would you feel?"

While Zeitoun was incarcerated, first at Camp Greyhound and then in a maximum-security prison, Kathy was, as she puts it, "battling her own demons". One of the gross injustices against them both was that Zeitoun was allowed no phone call, which left her in mounting despair. For two weeks she had no word from her husband, concluding in the end that he must be dead. Then, on 19 September, she learned of his detention from a missionary who called her after having seen Zeitoun in prison.

She dashed back to the city from Texas, where she had been staying with friends. The nadir came for her when she tried to find out the address of the courthouse where he was due to appear, charged with looting. Court officials told her they couldn't divulge such information as it was private.

"I cracked open at that point," she tells me. "How could the address of a courthouse be private? I cried harder then than I did at any other time. I felt like I was a little kid again – with no say-so, no rights, no voice. I felt lost."

Zeitoun was detained for almost a month before he was released on $75,000 (£50,000) bail for having looted his own house. The others fared worse: Dayoob, Gambino and Ronnie spent five, six and eight months in prison respectively, despite Zeitoun's efforts to prise them out. Eventually, the charges against all four of them were dropped.

Their experiences were just a blip in the civil rights catastrophe that was Katrina. Camp Greyhound held a total of 1,200 detainees in the aftermath of the hurricane, most of whom were African-Americans and all of whom suffered the indignity of having their right to habeas corpus removed.

As they approach the fifth anniversary of those events, the Zeitouns have managed with striking success to put their lives back together. The children are starting to sleep in their own beds again having for years insisted on cramming into their parents' for security.

Kathy has been diagnosed with symptoms of post-traumatic stress disorder, including memory loss and dizziness. "Katrina was a great reality slap. I was naive before – I felt I had things under control. But I've come to the conclusion that I don't control anything. I'm in control of nothing," she says.

Zeitoun still gets angry about the way he was treated, particularly as an American Muslim. "Muslim is a very simple word. Translated into English it means peace or believers. So why have these two nice, beautiful words been changed in people's minds to 'terrorist'?" he asks.

Despite that, he refuses to be bitter and vengeful. Instead, he dedicates his time to rebuilding the city, which is what he was doing when he was so late for our meeting. So far he has renovated a museum, some schools and about 250 houses damaged in the floods.

He says he is more disciplined now about his religious observance, making sure he at least is punctual for his five daily prayer sessions. He is also extra careful to follow all the civil rules – he doesn't speed or cut through red lights or park where he shouldn't. "I don't want to give these guys the chance to do the same thing to me again."

He has never even thought of abandoning the US. He refuses to bear a grudge, and says, for him, it remains a great country – you don't judge 300 million people on the behaviour of a few bad guys. Nor will he contemplate quitting New Orleans. "This is my home, my city. My life is here now," he says.

To prove the point to himself, perhaps, he plans to buy another boat; his canoe went missing following his arrest. This time, though, he wants a bigger model that would allow him to rescue people more easily.

But surely that suggests that he fears another Katrina, I ask him.

"It happened before," he says. "It can happen again."

Zeitoun by Dave Eggers is published by Hamish Hamilton in hardback on 15 March, £18.99.