Now grieving parents, many of whom dug through rubble with their hands in a frantic effort to save their children, are venting their anger at local officials who they claim knew the building was substandard.

Jumbled mounds of concrete and brick are all that remain of the three-storey schoolhouse that caved in just moments before afternoon classes were to begin. Notebooks, backpacks, clothes and a tin lunch box litter the picked-over rubble.

The scene is repeated in towns and cities across the quake-damaged section of Sichuan, where more than 50,000 people may have died, including hundreds of students crushed when their schools collapsed.

Bi Kaiwei's 13-year-old daughter, Yuexing, was in her second storey sixth-grade classroom when the walls and ceiling crashed down in the quake.

"Our child wasn't killed by the earthquake. She and the others were killed by a derelict building," he said. "The officials knew it was unsafe."

"Look at that one there," Bi said, pointing diagonally across from where the school used to stand to a yellowish corner building spared of damaged. "We live there. It was built in 1982. It's still standing."

Premier Wen Jiabao earlier this week stood symbolically on the rubble of another collapsed school in Sichuan and told students trapped below that they would be saved.

But that was little consolation in Wufu, where residents say the local government hasn't even announced the number of children killed in the school.

The loss of so many children is particularly poignant in China, where the government's family planning policies, aimed at curbing population growth, mean that most have only one child.

FRANTIC EFFORTS

When the New Number Two Primary School fell, parents, relatives and friends of pupils rushed to the site.

Sang Jun, a short, lively man, arrived about 20 minutes after the earthquake to look for his son. "There were already five people digging," said Sang. He jumped in to help.

His arms and legs, like Bi's and other parents here, are now scarred with scrapes and bruises from the frantic efforts to pull apart the rubble and get to their kids below.

Holding a pair of dirty blue jeans and a blue work shirt stained with blood, Sang said: "I was wearing these. I pulled out more than 20 children ... Only five were alive."

Zhang Chao was recovering from surgery in a hospital nearby. When he heard the school was demolished, he got up and went to help, pulling several bodies from the wreckage.

Down the road, a hefty farmer with a buzz cut named Zuo Jun hobbles with a crutch along a dirt path beside a golden field of wheat. Zuo injured his left foot prying through the rubble in search of his 11-year-old son, Zuo Hao, who appears pudgy with a crew cut and a jovial smile in family photos.

At the end of the raised path in the corner of the field is a mound of fresh dirt where Hao is buried.

"If the teachers had been there, he would be alive," said Zuo with a pained look. "During the lunch break, the teachers put two classes together, locked them in and then went to play mahjong. This is what students said."

SMALL GRAVES

Nearby fields are dotted with similar small graves. At one site, where three pupils were buried, relatives burn a pile of their child's clothes along with incense, hay and fake money.

Further along another farm path is the home of Yan Qiuyi, a classmate and close friend of Bi Yuexing's who survived. Her arm is in a sling because her shoulder was broken, her face is puffy and scarred, and she walks with a limp.

When her friend's parents approach, carrying a photo of their daughter striking a playful pose, tears flow from Yan's red, tired eyes. Speechless, Yan holds the picture to her face and cries.

Bi Yuexing's new grave is a mound of dirt ringed with small rocks in the shade of a bamboo stand and next to her great grandparents' remains. "The government told us to bury our children. There were too many to cremate," Bi said.

The parents of the victims are planning to meet on Monday morning at the school site to work out a plan to seek retribution, perhaps by suing the local education department.