AFTER the Great East Japan Earthquake and Tsunami of March 11, 2011, I worked with a post-disaster clean-up crew in a largely obliterated fishing port called Onagawa. We shovelled mud and debris, and did myriad odd jobs for newly homeless locals packed into evacuation shelters. Everyone had lost someone, and the more talkative survivors told us brutally upsetting stories of wives drowned in waterfront factories, elderly parents dragged away by the wave, entire families killed in their cars while trying to outrun it.

They spoke quietly, waving our useless condolences away, always mindful that their neighbour may have suffered worse. More than a few reminded us to consider the poor souls in the nearby town of Kamaya, where 74 children had been killed at Okawa Elementary School when the tsunami exploded up and over the adjoining river.

“In the context of the wider disaster, it was basically the worst thing that happened that day,” says Richard Lloyd Parry, a veteran English correspondent based in Tokyo, who reported extensively from the stricken Tohoku region. Currently on holiday back in the UK, he tells me that he often observed that same “peculiar humility of grief” I’d seen in Onagawa, “that communal sense of not wanting to attach more value to one’s own personal tragedy”. But the localised catastrophe at Okawa school emerged as a singular case, both pitiful and preventable, as outlined in Parry’s book Ghosts Of The Tsunami. “The event itself might be called an act of god,” he says.

“Tsunamis have always happened, and always will. And we can argue about sea walls and emergency planning, but in general Japan coped very well, probably better than any other country could have. At the same time, I’ve learned that all natural disasters have their politics too, and nowhere was this more manifest than at Okawa.”

Of the more than 18,500 people killed by the tsunami, very few were children, and almost every other school in the impact zone managed to keep its pupils safe. Okawa’s inability to do so, despite a steep hill behind the property and ample time to get the children up there, is presented by Parry as a study in “human and institutional failure”. His central narrative swirls around the black hole formed in those 45 critical minutes between quake and tsunami. He knows that its awful gravity may pull some readers in, and push others away.

“When people hear about Okawa, even in summary, they’ll often say they could never read a book on the subject. The needless mass death of all those little children … So the task was to write something that wasn’t just depressing and sad. I didn’t need to sensationalise, or sentimentalise. The story itself was so dramatic, so full of emotion, that the job was to step back and simplify.”

But Parry has not written a straightforward journalistic account either. The book does cover the Okawa parents’ divisive campaign to find out exactly what went wrong, the authorities’ shabby obfuscations, and the long court battle that resulted. Parry draws on all the available evidence to consider the “timidity, complacency and indecision” that proved so fatal at the school as symptoms of a broader modern Japanese malaise. The flipside of that nation’s fabled stoicism, so inspiringly enacted after the tsunami, is posited as a corrosive kind of inertia, “a collective lack of self-esteem”.

True to its title, though, this is also a book about ghosts. The tsunami created thousands of them, in a country where formal religion plays almost no part in daily life, yet the general population maintain a deep, instinctive belief in the abiding spirits of their ancestors. Tohoku, with its moaning winds and lonely forests, was already known for a certain eerie, folk-tale atmosphere even before the disaster. After came an outbreak of hauntings.

Parry tells of taxi drivers taking phantoms to addresses where the houses had been washed away, and visits from drowned relatives, oblivious to their own deaths, who left seat cushions soaked in salt water. Among his most compelling interview subjects is Zen priest Taio Kaneta, who was called to perform exorcisms on a builder from his parish and a nurse from Sendai. Neither was directly affected by the disaster, but both were apparently possessed by enraged and bewildered spirits of the recently deceased.

“So, whatever the origins of their bizarre experiences,” says Parry, “it wasn’t personal grief. I don’t, myself, see any reason to believe in the supernatural, but neither do I think it matters whether these ghosts were real. You can view them as literal visitations, or as manifestations of a profound psychic blow, affecting not just individuals and communities but an entire society.”

He does not exclude his own experience, having felt the earthquake in Tokyo on the same day that the first ultrasound pictures were taken of his unborn youngest child. The capital was rattled but intact, and went about its business – which was soon to include planning for the next Olympics, even while preparing for the next big quake. Parry writes about his adoptive hometown as a real-world equivalent of Octavia, the “spider-web city” imagined by the great modernist-fabulist Italo Calvino, hanging precariously over an abyss.

And then there is that other world of “death and destruction”, which he passed into every time he crossed the tsunami inundation line. “I wanted to go, but I dreaded it,” he says. “You tell yourself you have a job to do, not as vital as aid work but perhaps similar. You try to be warm and sympathetic but detached and professional. You want to be of use.”

Even so, he cried many times while talking to the mothers of lost Okawa children, and the smallest details of their suffering are the most devastating to read. Sayomi Shito licked the mud from her dead daughter Chisato’s eyes, because there was no clean water available. Naomi Hiratsuka trained to operate a heavy-duty industrial earth-mover so that she could take a more active role in the search for her own daughter Koharu, whose remains were found much later. Hiratsuka went on to find more comfort in consulting a shaman – who claimed to commune with Koharu, and assured her that the disaster was effectively predestined – than in pursuing the legal case against the local board of education.

For his own part, Parry did not disagree that mistakes had been made by the Okawa teachers (10 of whom were also killed), nor that school and city bureaucrats had closed ranks to attempt a cover-up of the most “inconsistent, banal and transparent” kind. But where some of the parents saw a grander conspiracy, Parry saw only “stubborn, clumsy, charmless men” whose quasi-culpability could never satisfy the plaintiffs’ grief. He came to think of their struggle as a reckoning with the unfathomable – “the fiery fact of death.” “The true mystery of Okawa school was the one we all face,” he writes.

“No mind can encompass it; consciousness recoils in panic. Extinction of life: extinction of a perfect, a beloved child: for eternity. Impossible! the soul cries out. What are they hiding?” The families got a payout in court in lieu of answers from the universe, a quotidian win to set against their existential loss. And Parry got the sense that such loss may only be comprehensible in the most abstract terms. He’s no Buddhist, but admired the “beauty of detachment” shown by Reverend Kaneta. A Zen perspective allowed the priest to tirelessly support survivors, and mitigate the damage to his own psyche, by reflecting on the tsunami as a recurring physical and metaphysical process, a “mechanism” of the cosmos.

“It’s not easy to confront tragedy and suffering,” says Parry. “It’s surely even harder to take a step back and see these things as natural, or inevitable. If you can do that, death and disaster might not seem as soul-crushing or life-denying as they first appear. I don’t think I could do it myself, especially if I had lost a child. But perhaps it’s something to aspire to.”

Ghosts Of The Tsunami is published by Jonathan Cape, £16.99