'I was reminded of 9/11 and Hurricane Katrina – but the damage here is of a different degree'

David Usborne reports from the tornado-hit city of Joplin, Missouri, where the physical destruction is immense but the emotional scars are even greater

Tomorrow the President comes to Joplin to help with that thing they call closure.

A few folk may be ready. "We know what needs to get done – let's get started," says Preston Miller, 15, standing in what used to be a friend's bedroom looking across ruined homes to his high school that is no more. Most do not feel the same.

Even Preston, with his adolescent capacity to process calamity, is not so untouched. Schoolmates are missing, including Will Norton, the young man who was sucked through the sunroof as drove home with his father from his own graduation ceremony. Missing too is almost a third of the city he has grown up in. There is no moving on yet. Everything is too raw.

You can't witness what last Sunday's tornado left behind and not react physically. The blasphemies uttered when the first Twin Tower collapsed came back to this reporter as well as memories of the Lower Ninth after Katrina – there are those red Xs again on homes that have been searched. Here, though, unfathomable power was focused on so tightly a defined area that the damage is of a different degree.

Only those who lived through it can tell you what it is like to be swiped by nature's worst wrath. Some say their bodies were pulled and pushed "like a rubber band". Everyone speaks of the roar. There is no agreement on how long it took to pass. Some say it was over in seconds, others say 15 minutes. While there was fear, of course, a few recall feeling entirely calm.

Different details of the huge canvas of destruction left behind will strike and stay for ever with one person but not the other. The leg of a plastic doll lying in the grass beside what used to be a low-income housing development, and a girl's diary with pictures of buff men printed on every page. The twisted girders of the Home Depot store that is so mashed you don't know at first what you are looking at.

Coat-hangers make one mental souvenir. Walk these streets and look into ruined homes and you marvel at kitchens and bedrooms rudely exposed in a sort of model-home mockery. A packet of porridge oats there, mugs all in a row there. How is it, though, that nearly every cupboard still has the coat-hangers on the rail, sometimes still with clothes on?

There will be stages of shock and pain for the people of Joplin, a small enough town for everyone to be affected. It may be the simple act of grasping that landmarks are gone – that building south of downtown that was the hospital will have to be demolished. Ask New Yorkers about that. Or the longing for lost loved ones. Or they will have experienced things that years from now they still won't be able to talk about.

What will Khya Hobson, who was in church with her husband, Jason, when the tornado tore through, do with the memory of arriving back to her home and finding a pick-up truck on the street with the driver impaled through the chest by a two-by-four? How does Katie Simpson, 17, handle the memory of running to check on her grandma and passing countless dead bodies along the way, as if from a plane crash, some decapitated?

When the pain finally erupted for Laramie Sweet on Thursday afternoon in the car park of a Food4Less supermarket her features seemed almost to dissolve and she could not speak. She and her brother, Paul, had been queuing with other disaster victims for aid packages, including food, clothing and medicines. When it was their turn, a volunteer asked, "How many in your family?"

How many in your family? Such a simple question. But here it's grotesque. She swallows and then lets out a brief wail. "Three," she finally manages. "I guess. Three. I don't know. I'm sorry. I can't find my dad." Those last words are blurted almost like a plea for help. A few minutes earlier she had told her story – how four has become three – and the telling of it was almost more than she and her brother could stand.

Her father and mother were at Pizza Hut by Home Depot when the sirens went off. With the other patrons, they huddled in the restaurant's cold storage room. They held hands tightly. Their mother, Vickie Sweet, blacked out after the wind started. When she woke up she was covered in blood and in a car being taken to hospital. Pizza Hut was gone, completely. And so was her husband. Just gone.

"He got pulled away," Laramie says, tears streaming. She says she still has hope that her father might be found alive, perhaps in a hospital, but her sodden cheeks tell you she is nearly at the end of that thread. "It has been a long time, it's hard. We've called everywhere." Paul has pleaded in vain to get into the city morgue to look for his father. "They said there are too many bodies, they were still coming in," he said.

This is the worst agony of Joplin. Laramie and Paul and scores of others are in the cruellest of all limbos. Their lost ones appear to have been taken but to where exactly? They burst to grieve but dare not let that strand of hope snap, because to do so would be to betray the one who is missing. You can't give up on a person when there is no body. And you can't grieve when there is no body. Echoes of 9/11 again.

Surviving the storm does not mean escaping the emotional hurt. Like so many others, Tanya Rodriguez, 44, cannot get through her story without crying. Because she and her 15-year-old son, Keenan, came so terribly close. They were driving in her car. Suddenly fearing a tornado might be coming, she drew into the car park of Dillons, another supermarket, intending to take cover inside. But they were too late.

"It picked us up and dropped us straight down again. Bang," she recalls. Then everything was calm and she looked down at her son crouched on the car floor and asked if he was OK. He didn't answer or move. "I thought, you know..." she said, the tears beginning. But Keenan stirred and started to get up, when the roar started again. As well as the noise, Ms Rodriguez remembers a smell. "I think it was the smell of fear."

The tearing wind wrought a maelstrom of crashing metal and steel in the car park. When it was over, her son had been struck in the back by a piece of steel rod that had come through the seat. The car had been crushed tightly between two others. Someone else's car, a black SUV, had landed on top of it. Her son was not seriously injured. She has been picking glass from her scalp for days, but, incredibly, is otherwise fine.

Barack Obama will speak of the myriad miracles of survival like that one. And he will share stories of those who risked their lives again to help others. He will speak also of rebuilding the hospital and the high school that Preston wants back. But even he will not be able to describe adequately what one angry twisting funnel of cloud did to this town and its people last Sunday. It is hard for any of us to understand.