Lying in his hospital bed in Chengdu, 18-year-old Xue Xiao recalls how they recited a roll call of survivors in the dark debris of his high school after the 8.0-magnitude quake that rocked southwest China's Sichuan Province on May 12.

He was having a chemistry class at 2:28 PM that day at Dongqi High School of Mianzhu City, when the classroom suddenly jolted violently.

Students had just taken cover under their desks before the building collapsed. Xue felt the floor disappearing from under him and he fell. Suddenly it was dark and silent. Some began weeping.

"Is anybody there? I'm Long Rui," called a voice from overhead. Then more voices were heard: "I'm Li Chunyang", "I'm Xiao Xing." The familiar voices calmed Xue buried in the ruined building. "I'm Xue Xiao," he called out.

His right hand was stuck under a pre-cast concrete slab. He could only move his left hand and leg. His only comfort came from a crack overhead, through which he could see dim sunlight.

When the light went out, he knew it was night. The teenagers sang and talked about what they would do when they got out. Some just wanted to "drink water".

Rescuers were busy outside, but he could not know if anyone was rescued. He felt tired and told a nearby girl Ma Xiaofeng, "I get to take a nap for two minutes. Remember to wake me up." But Ma wouldn't agree, and kept calling Xue's name to keep him awake.

In the next roll call, two schoolmates did not answer. He feared the worst, but did not panic. He felt he could survive, or he would still be among his friends if he did die.

When he heard students being rescued, he felt anxious, "When it will be my turn?" He had no hunger - just a tremendous thirst.

The rescuers retreated once because of aftershocks. When they returned, Xue asked the rescuers outside, "You won't abandon me, will you?"

"We will save you," came the answer.

"Then, can you work faster? I might not stand it much longer."

This conversation repeated several times before one rescuer asked, "What do you want to do when you get out?"

"I want a Coke. An iced Coke," he replied. "I'm so thirsty."

"Okay. I'll buy you Coke."

"Then what can I buy for you?" asked Xue.

"You can buy me an ice cream when you get out."

"No problem."

Coke and ice cream - it was a deal.

At about 7:00 PM on the fourth day, the concrete slab was lifted and Xue was taken out. He had been buried for almost 80 hours with no food and no water.

Lying on the stretcher, he remembered the deal: "Uncle, I want Coke. Iced Coke." His words spread across the country when the rescue was shown on television. He was widely known as "Coke boy".

Xue's right arm was amputated in hospital. "I will get better. I want to study and go to college," he said.

Peng Jia, a publicity official of the Dongqi (Oriental Steam Turbine) Factory, said more than 200 students were buried in the school affiliated to the factory.

Of those buried students 145 are dead and 80 missing, according to the latest statistics from the school's official blog on Sohu. Xue Xiao and Ma Xiaofeng are among few lucky ones rescued from the debris.

They had come so close to joining the statistics from the quake: 68,109 dead and 19,851 still missing as of May 28.

The first 72 hours after a quake is widely believed to be the window of survival for those buried. People can survive with no serious injuries, but beyond 72 hours, the chances of survival drop markedly because of failing physical functions, anxiety and despair, said Lan Zhixiang, a doctor from Guangxi Zhuang Autonomous Region who headed a volunteer rescue team to Sichuan.

"A strong will to live, however, can lead to a miracle," he said "Those with a strong will can control their emotions better and maintain their physical strength."

Wang Youqiong aged 60 was saved after being buried for 196 hours in Yinchanggou, Pengzhou. The television footage shows her crying, "Don't tell my son, he has to work," as she was carried out, worrying about causing her son troubles.

She was swept away in a mud-rock flow and trapped between two rocks. It rained one day and she drank rainwater. Two survived dogs licked her lips and face, which doctors believe helped her survive.

Peng Zhijun was another miracle survivor who was buried for 100 hours under the debris in Beichuan County.

He could only move his right arm. "I untied my belt, and used it to tie my injured left arm to my head to relieve the pain. Then I started thinking about food and water. I searched my pockets and found half a pack of cigarettes and a few pieces of napkins."

He ate the cigarettes and the napkins to keep survive.

"I also drank my own urine. I managed to take off one of my shoes and used it to collect urine," recalled Peng, lying in the Mianyang City Center Hospital. More than ten people had been buried alive near him. Peng told them to drink their urine, but they all refused, except the three ones who survived.

Doctor Lan said water is key to survival. "Urine is mostly water and other substances in urine like urea are harmless. It's an effective way to prolong life in an extreme environment."

Peng said, "Natural disasters can't be avoided. I had to save myself. So long as you persist in your belief, you can have one more minute of life and one more chance to be rescued."

(Xinhua News Agency May 29, 2008)