Mu Lai Chao watched the building collapse on her son.
In an instant the ground had shaken and the smooth walls had buckled and now there were only piles of concrete trapping hundreds of schoolchildren. Her husband ran to the rubble, pulling the injured out.
"He saw them buried," she told ABC News in Chongqing. "One was bleeding heavily from the leg."
Her son survived but four of his classmates were killed, part of the deadly toll from China's worst natural disaster in three decades, a three-minute-long, magnitude 7.9 earthquake that struck China's most populous province Monday afternoon.
The horrific dimensions of the destruction and loss of life continued to grow as rescuers clawed through demolished towns and cities only to find heartbreak and misery.
The death toll in Sichuan Province alone has topped 12,000, with an additional 18,645 still buried in the rubble of the city of Mianyang, the official Xinhua News Agency reported today.
State TV quoted He Biao, director of the emergency office in the Aba region, saying that soldiers who marched to the town of Yinxiu believe that only 2,300 of the town's 9,000 people survived.
The killer quake arrived when schools and other public buildings were packed, leaving many schoolchildren among those buried in the flattened buildings.
Government rescue workers today finally reached Wenchuan county, the epicenter of the earthquake, only after hiking through rugged terrain. Heavy rain and roads studded with boulders have hampered the search effort.
More than 30,000 troops are deployed by the government in and around the epicenter, which is located in the country's teeming Sichuan province.
It is home to one out of every 50 people on the planet, with many villages hard to reach, lodged in the mountains where roads are easily blocked and helicopters could not land today because of the bad weather.
About 300 aftershocks have rattled the region since the earthquake, including a handful that measured between magnitude 4 and 6 today. People have been sleeping in tents, afraid to return to their homes, making the massive task of rescue workers all that much harder.
"The situation is worse than we previously estimated," Chinese Prime Minister Wen Jiabao told aid workers in Dujiangyan, a city 45 miles from the epicenter, according to Xinhua, the official news agency. "At present, we have great difficulties carrying out our rescue work."
In Dujiangyan, television images show a town that looks like it was hit by an airstrike. Bodies dug from the rubble are being lined up on the road. The air is filled with sirens and dust. Rescue teams have been trying to reach a woman who is eight months pregnant, trapped beneath a seven-story apartment building.
At least eight schools in Sichuan province literally crumbled when the earthquake hit. At one school, fewer than 100 of 420 students survived, Xinhua reported.
In Juyuan, 60 miles from the epicenter, a three-story middle school collapsed into a pile of rubble 5 feet high, burying as many as 900 students.
"Some had jumped out of the window and a few others ran down the stairs that did not collapse," a teacher told Xinhua. Cranes have been brought in, but there is no power. The town's hospital was also destroyed in the earthquake. The bodies of 50 dead children have been taken out of the rubble.