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A large crack (C) appears on a building in Chengdu, in southwest China's Sichuan province on May 12, 2008, after an earthquake measuring 7.8 rocked the province. The tremor, centered 92 kms northwest of Chengdu, was felt as far away as Beijing and Shanghai and the Thai capital Bangkok, where office buildings swayed with the impact. AFP PHOTO/XINHUA (Photo credit should read AFP/AFP/Getty Images)

This television frame grab taken in Beijing from China's state television channel CCTV shows rescue workers with dogs getting on a plane in Wenchuan, in southwest China's Sichuan province, where a powerful earthquake struck on May 12, 2008. At least 7,600 people have been confirmed killed by the earthquake which measured 7.8 on the Richter scale and according to state media reports, the death toll could rise dramatically. RESTRICTED TO EDITORIAL USE AFP PHOTO / CCTV (Photo credit should read AFP/AFP/Getty Images)

DUJIANGYAN, CHINA - MAY 12: (CHINA OUT) Soldiers attempt to rescue people buried in the rubble of buildings destroyed by an earthquake on May 12, 2008 in Dujiangyan, China. A major earthquake measuring 7.8 on the Richter scale jolted Wenchuan County of Sichuan Province on May 12, 2008. Chinese Premier Wen Jiabao is visiting cities worst hit by the earthquake, including Duijiangyan which is 98km for the epicentre, as rescue efforts continue. (Photo by Wang Xiwei/ChinaFotoPress/GettyImages)

DUJIANGYAN, CHINA - MAY 12: (CHINA OUT) Soldiers attempt to rescue people buried in the rubble of buildings destroyed by an earthquake on May 12, 2008 in Dujiangyan, China. A major earthquake measuring 7.8 on the Richter scale jolted Wenchuan County of Sichuan Province on May 12, 2008. Chinese Premier Wen Jiabao is visiting cities worst hit by the earthquake, including Duijiangyan which is 98km for the epicentre, as rescue efforts continue. (Photo by Wang Xiwei/ChinaFotoPress/GettyImages)

DUJIANGYAN, CHINA - MAY 12: (CHINA OUT) An injured person waits to receive medical attention on the street after the collapse of the hopital following an earthquake on May 12, 2008 in Dujiangyan, China. A major earthquake measuring 7.8 on the Richter scale jolted Wenchuan County of Sichuan Province on May 12, 2008. Chinese Premiere Wen Jiabao is visiting cities worst hit by the earthquake, including Duijiangyan which is 98km for the epicentre, as rescue efforts continue. (Photo by Wang Xiwei/ChinaFotoPress/GettyImages)

DUJIANGYAN, CHINA - MAY 12: (CHINA OUT) An injured man receives medical attention in a n ambulance after the collapse of the hopital following an earthquake on May 12, 2008 in Dujiangyan, China. A major earthquake measuring 7.8 on the Richter scale jolted Wenchuan County of Sichuan Province on May 12, 2008. Chinese President Hu Jintao is visiting cities worst hit by the earthquake, including Duijiangyan which is 98km for the epicentre, as rescue efforts continue. (Photo by Wang Xiwei/ChinaFotoPress/GettyImages)

HENAN, CHINA - MAY 12: (CHINA OUT) Workers clean the quake destroyed gate of a hospital on May 12, 2008 in Henan, China. A major earthquake measuring 7.8 on the Richter scale jolted Wenchuan County of southwest China's Sichuan Province at 2:28 pm Monday. The current confirmed death toll stands at at least 8,500 people. Beichuan county is one of the worst-hit areas some 50km from the epicentre with 80 per cent of buildings reported destroyed. The death toll is expected to rise, as nine hours after the quake hit, rescue teams have yet to reach the epicentre in Wenchuan county, Xinhua news agency reported. (Photo by Luo Gensheng/ChinaFotoPress/Getty Images)

(FILES) This file picture taken on February 9, 2007 shows a panda at the China Conservation and Research Centre for the Giant Panda in Wolong, in China's southwestern province of Sichuan. China's State Seismological Bureau said on May 12, 2008 that the epicenter of a massive 7.8 magnitude earthquake was in Wenchuan County, a mountainous region home to the Wolong Nature Reserve, China's leading research and breeding base for endangered giant pandas. The quake, which has killed at least 100 people, was felt in cities across a swathe of southeast Asia including the Thai capital Bangkok, more than 1,800 kilometres (1,200 miles) from the epicentre in Sichuan province. AFP PHOTO / FILES / LIU Jin (Photo credit should read LIU JIN/AFP/Getty Images)

DUJIANGYAN, CHINA - MAY 13: (CHINA OUT) Rescue workers search for victims in the debris of a building that collapsed in the earthquake, 96km from Wenchuan, the epicenter of the quake in west China's Sichuan province on May 13, 2008 in Dujiangyan, China. (Photo by Liu Xingzhe/ChinaFotoPress/Getty Images) 392777973

DUJIANGYAN, CHINA - MAY 12: (CHINA OUT) The body of a victim lays amidst rubble of a collapsed building after an earthquake, 96km from Wenchuan, the epicenter of the quake in west China's Sichuan province on May 13, 2008 in Dujiangyan, China. (Photo by Liu Xingzhe/ChinaFotoPress/Getty Images) 392777973

DUJIANGYAN, CHINA - MAY 13: (CHINA OUT) Rescue workers search for victims in the debris of a building that collapsed in the earthquake, 96km from Wenchuan, the epicenter of the quake in west China's Sichuan province on May 13, 2008 in Dujiangyan, China. (Photo by Liu Xingzhe/ChinaFotoPress/Getty Images) 392777973

A mother mourns a Chinese soldiers carry the body of her child who was killed when a school building collapsed during the 7.8 magnitude earthquake in Dujiangyan, in southwest China Sichuan province on May 13, 2008. The confirmed death toll from a massive earthquake in southwestern China has risen to nearly 12,000, a government official said on May 12. AFP PHOTO/TEH Eng Koon (Photo credit should read TEH ENG KOON/AFP/Getty Images)

NANJING, CHINA - MAY 13: (CHINA OUT) Medical staff who will go to Wenchuan, the epicentre of a 7.8 Richter squale earthquake, pose for a photo before they board their plane at Nanjing Lukou airport on May 13, 2008 in Nanjing, China. Some 1,300 rescue and relief troops arrived for the first time in Wenchuan County, the epicentre of Monday's major quake which has killed more than 10.000 so far. (Photo by Wu Jun/ChinaFotoPress/Getty Images)

NANJING, CHINA - MAY 13: (CHINA OUT) Medical staff who will go to Wenchuan, the epicentre of a 7.8 Richter squale earthquake, pose for a photo before they board their plane at Nanjing Lukou airport on May 13, 2008 in Nanjing, China. Some 1,300 rescue and relief troops arrived for the first time in Wenchuan County, the epicentre of Monday's major quake which has killed more than 10.000 so far. (Photo by Wu Jun/ChinaFotoPress/Getty Images)

A man shows the damage to cars and buildings a day after a 7.8 magnitude earthquake hit the town of Hanwang in Sichuan Province on May 13, 2008. China's biggest earthquake for a generation left tens of thousands dead, missing or buried under the rubble of crushed communities, plunging the nation into an all-out aid effort. Troops and rescue teams struggled by air, land and water to reach areas of southwestern China stricken by the huge quake that demolished schools, homes and factories. AFP PHOTO/Mark RALSTON (Photo credit should read MARK RALSTON/AFP/Getty Images)

CHENGDU, CHINA - MAY 13: (CHINA OUT) People rest outdoors following an earthquake in the morning of May 13, 2008 in Chengdu of Sichuan Province, China. According to state media, a major earthquake measuring 7.8 on the Richter scale jolted Wenchuan County of southwest China's Sichuan Province May 12, killing at least 10,000 people. The death toll is expected to rise as there is no definite estimate of the number of people trapped under mounds of concrete. (Photo by China Photos/Getty Images)