China's worst earthquake in more than 30 years struck southwest China on May 12, 2008, killing more than 80,000 people, including thousands of children who were crushed to death when their schools collapsed on them.
- Rebuilding to cost billions
- China praised for swift response
- Scandal over collapsed schools
More than 374,000 people were injured and millions left homeless when the 8.0 magnitude quake struck southwestern Sichuan province. Its epicentre was in the mountainous county of Wenchuan, where nearly 24,000 died or are counted as missing - about a fifth of the population.
Thousands of aftershocks, heavy rainfall and landslides compounded the difficulties for military, government and private workers trying to deliver shelter and aid.
The earthquake was by far the worst since the devastating 1976 quake in the northeastern city of Tangshan that killed up to 300,000 people. The U.S. Geological Survey said the Sichuan quake struck at 0628 GMT at a depth of 10 km (6 miles). The aftershocks killed more people and brought down further buildings.
In the worst-hit regions - the hilly, rural area of Beichuan and Wenchuan to the southwest - buckled and blocked roads made it difficult for rescuers and supplies to get through. China mobilised 130,000 army and paramilitary troops to the area, some of them hiking in on foot.
Buildings toppled in at least six counties near the epicentre, according to the Chinese news service Xinhua. Although most of the focus has been on Sichuan, the quake also affected Gansu and Shaanxi provinces, striking areas that are predominantly poor.
CLAMPDOWN ON PARENT PROTESTS
Public anger has focused on the poor state of school buildings, with many blaming lax building controls and corruption for shoddy construction.
China says 5,335 schoolchildren were killed while other estimates have put the figure at between 7,000 and 9,000. Grieving parents have likened the school buildings to soft "tofu dregs". They accuse officials or builders of cutting corners and pocketing money meant to be used to construct stronger classrooms.
The government ordered a nationwide safety inspection of all public buildings after the disaster. It also launched an inquiry into why so many schools crumbled. This concluded they collapsed because of the size of the quake rather than construction flaws.
Beijing fears that the anger of bereaved parents could trigger unrest, especially around the one-year anniversary. It clamped down on media coverage in the aftermath of the quake and has arrested activists trying to seek justice. Parents demanding inquiries have been detained in "black jails" - informal detention rooms in hotels and offices, according to Amnesty International.
Chinese lawyers and human rights activists who have offered help to grieving families have also been intimidated and detained, and their efforts to bring cases to court have been stymied, Amnesty says in a report.
A month before the anniversary, China said it would spend an extra 8 billion yuan ($1.17 billion) on making schools in earthquake-prone areas safer.
China launched a massive aid operation immediately after the quake, sending in troops to rescue people trapped in rubble, organise evacuations and deliver aid. Scores of aircraft were also deployed.
The quake marked the first time that China had asked for outside assistance to deal with a major disaster. But U.N. agencies and international groups played a relatively minor role - partly because China has significant resources and long experience in dealing with large crises.
Western commentators have praised China for its swift reaction and openness, contrasting it with Myanmar's secretive response to Cyclone Nargis which had struck just over a week earlier. Myanmar blocked foreign aid for several weeks.
One of the most immediate needs in the quake zone was shelter. Hundreds of thousands of tents and temporary housing units - simple steel structures normally used by construction workers - were brought into the area.
China's ambitious aim is to get everyone back into permanent housing within a year or two. But the destruction was vast - officials have said 4.8 million people lost their homes. Francis Markus, the China spokesman for the International Federation of Red Cross and Red Crescent Societies, said his organisation likened the magnitude of the task to rebuilding Los Angeles or Osaka.
Survivors are desperate not to spend another cold winter in temporary dwellings. And in the wait for relief, some have made angry claims about corruption, favouritism or delays.
The government has promised 1 trillion yuan($147 billion) for post-quake rebuilding, although Jiang Jufeng, governor of Sichuan province, has said 1.7 trillion yuan is needed for the task.
The government is offering building subsidies of between 16,000 and 26,000 yuan for homes and loans of 50,000 yuan that are first interest-free and then low-interest. But building a house costs between 70,000 and 100,000 yuan or more.
Markus said that one year on there were still lots of people who could not start rebuilding their homes, including those unable to get bank loans because they are too old to qualify or too poor or don't have a stable source income.
The town of Beichuan, which is surrounded by mountains, was so badly devastated that it will be rebuilt on an absolutely flat river plain to the south. The plan is to turn the old town into a memorial site.
The U.N. Food and Agriculture Organisation (FAO) has said the quake caused damage worth $6 billion to the region's agriculture.
More than 30 million people in rural communities lost most of their assets, thousands of hectares of farmland were destroyed and millions of farm animals died, the FAO says.
The agency, which says China has asked it to coordinate agricultural rehabilitation in Sichuan, predicts it will take three to five years to rebuild the sector.
The World Health Organisation says up to 10 percent of those affected by the earthquake will need long-term mental health care. The agency is consulting with the Chinese government on rebuilding hospitals to withstand future natural disasters.
Immediately after the quake officials were also worried about possible damage to dams and the numbers of rivers that were blocked by landslides, forming more than 30 "quake lakes". Premier Wen Jiabao warned of the risk of "secondary disasters" caused by heavy rains and ordered experts to inspect dams and reservoirs on regular patrols.
Authorities evacuated about 250,000 people living downstream of the largest such lake, Tangjiashan. In June 2008, floodwaters from the lake were released and swamped low-lying areas in Beichuan.
China was also put on precautionary alert against possible radiation leaks. The disaster area is home to China's chief nuclear weapons research lab in Mianyang, as well as several secretive atomic sites, but no nuclear power stations.