CHENGDU, China — It was the middle of the afternoon, one of the worst possible times for the powerful earthquake to strike.

The three-story high school in the town of Juyuan collapsed, trapping up to 900 students under slabs of concrete and steel. Two chemical plants in the town of Shifang toppled onto hundreds of workers and unleashed 80 tons of toxic liquid ammonia.

Across central China, the toll from Monday's 7.9 magnitude quake rose to nearly 10,000 dead — the worst to hit the country in more than three decades.

For nearly three agonizing minutes, the quake shook the region of small cities and towns set amid steep hills north of Sichuan's provincial capital of Chengdu. It emptied office buildings about 900 miles away in Beijing and could be felt as far away as Vietnam.

State media and photos posted on the Internet underscored the immense scale of the devastation.

At least 50 students died in the high school in Juyuan, south of the epicenter, Xinhua said. Photos showed people using cranes, mechanical hoists and their hands to remove slabs of concrete and steel.

Buried teenagers struggling to break free from the rubble, "while others were crying out for help," the official Xinhua news agency said. Families waited in the rain near the wreckage as rescuers wrote the names of the dead on a blackboard, Xinhua said.

Parents of the dead students built makeshift religious altars at the site, resting the corpse on any available piece of plywood or cardboard, and burning paper money and incense in a traditional honor for their child in the afterlife, according to NPR's Melissa Block.

The earthquake hit one of the last homes of the giant panda at the Wolong Nature Reserve and panda breeding center, in Wenchuan county, which remained out of contact, Xinhua said.

In Chengdu, it crashed telephone networks and hours later left parts of the city of 10 million in darkness.

"We can't get to sleep. We're afraid of the earthquake. We're afraid of all the shaking," said 52-year-old factory worker Huang Ju, who took her ailing, elderly mother out of the Jinjiang District People's Hospital. Outside, Huang sat in a wheelchair wrapped in blankets while her mother, who was ill, slept in a hospital bed next to her.

Xinhua reported Tuesday morning that the death toll was approaching 10,000, but did not provide a more precise figure. It said the vast majority of the fatalities occurred in Sichuan with 216 more deaths in three other provinces and the mega-city of Chongqing.

Worst affected were four counties including the quake's epicenter in Wenchuan, 60 miles northwest of Chengdu. Landslides left roads impassable Tuesday, causing the government to order soldiers into the area on foot, state television said, and heavy rain prevented four military helicopters from landing.