As the Chinese government orders an investigation into the collapse of school buildings in the recent earthquake, Daniel Griffiths travels to one town in Sichuan province where, he says, they still do not know how many children are buried under rubble.
The basketball hoops in the playground of Juyuan school were still standing when I arrived, a reminder of another time, a time before the earthquake.
But instead of children playing games there were rescue workers wearing face masks, police in their blue uniforms and Wellington boots, soldiers and distraught relatives - a heaving crowd of hundreds, all packed into the muddy playground.
In one corner there was a red, blue and white striped awning. Underneath were the bodies of the children who had already been found in the wreckage.
All attention was on the white pile of rubble, concrete and twisted steel that was the former school building. The ruins lay behind some tall poplar trees, their green leaves heavy in the thick, hot afternoon.
Large yellow cranes slowly lifted chunks of masonry up and away from the wreckage. Teams of rescue workers and medics picked their way through the debris, perhaps hoping to hear a cry or see some movement under the rubble.
But there was nothing.
I stood watching, the hot Sichuan sun burning my neck, almost refusing to believe that there were children somewhere there in the ruins.
So many lives waiting to be lived, maybe they would have been doctors, teachers or farmers. Husbands or wives, parents themselves. Now all that possibility, all that potential was gone.
Pile of rubble
In the crowd nearby were Mr and Mrs Fu. A large, cheery man with striped T-shirt, Mr Fu motioned towards the wreckage.
Hundreds of staff and students were trapped in Juyuan Middle School
"These used to be classrooms," he said, as we stood there trying to take in what had happened.
Alongside the pile of rubble there was another school building. It was still standing.
It had been left just as it was the moment the earthquake hit.
As I peered into the classrooms, I could see books scattered all over the floor, a couple of desks overturned in the rush to get outside.
There was still writing on the blackboard by the classroom door, which now hung wide open.
Mrs Fu had come down to comfort a member of her family whose 16-year-old son was still stuck inside. He was her only child.
She had not slept since the earthquake, Mrs Fu told me.
Cries for help
The boy's mother was sitting on a classroom chair with some of the other parents in the muddy playground, her hair pulled back, eyes red-rimmed, blue plastic coat pulled over her knees.
She had not lost hope.
"You can hear people calling for help in there," she said, "but there is just no way to reach them."
An ambulance had just arrived. Maybe they could help, she said. But there seemed to be little chance.
Throughout the day, rescue workers kept on bringing out the bodies of children.
Noisy firecrackers echoed around the playground. Traditionally they are used for happy occasions like weddings or the Chinese New Year but now they were being lit each time another body was brought out.
The sound of joy had become the sound of sorrow.
Suddenly the crowd panicked and surged across the playground away from one of the other buildings. People said they had seen it swaying.
The recovery operation continues day and night
"Another earthquake," a woman shouted.
There was no aftershock this time but you could feel the fear and also the sense of loss.
An older woman came up to me. She had been there at the school all day, her dark hair dyed, her clothes a simple pair of jeans and T-shirt.
She must have been in her 50s but she looked much older.
"All those children in there they'll all have been an only child," she told me pointing at the school.
"Because, you know, in China most of us are told to have just one child. They won't have any brothers or sisters."
Tragedy has come on top of tragedy.
Now the town of Juyuan faces the prospect of a lost generation of children. And this school building was not the only one to collapse. There were many more.
The government has launched an investigation. It has promised to punish anyone found guilty of shoddy construction.
But all that will mean nothing for the parents of the children who have already died.
It was dark by the time I left, but the school playground was still full. Parents and rescue workers all prepared to spend another night out in the open, hoping against hope they would find one child still alive.
From Our Own Correspondent was broadcast on Saturday, 17 May, 2008 at 1130 BST on BBC Radio 4. Please check the programme schedules for World Service transmission times.