A magnitude 8 earthquake occurred in south western China's Sichuan province on May 12, sending tremors to over half of China. When the quake first happened, the Chinese official rated it as 7.8 on the Richter scale, but it was revised to magnitude 8 on May 18 after sourcing for more data, including those from monitoring facilities abroad.

As of May 18, the death toll was over 30,000. Over 102,000 were injured, 12,300 were still under debris, and 134,000 rescued. The official estimated that the death toll could rise to at least 50,000.

The epicenter was Wenchuan of Aba autonomous prefecture for the Qiang and Zang (Tibetan) minorities. Wenchuan is a county some 90 kilometers away from Sichuan's capital Chengdu. It has a population of about 110,000, and is one of the only four habitations for the Qiang minority in China.

The county also offers the only access way to the national reserve of Wolong, the home of pandas, and world reserve of Jiuzhaigou and Huanglongsi. The quake had left many tourists trapped, but the 86 pandas in Wolong were reportedly intact.

Other severely-hit areas include Beichuan, Dujiangyan, Mianyang, Deyang, and Pengzhou. Landslides, aftershocks and affected dams exerted threat to rescue work.

The state-run new agent Xinhua reported on May 15, quoting Chinese Premier Wen Jiabao that the quake had a stronger impact than the last massive one in Tangshan 32 years ago, which killed 255,000 people. The size of the strongly-stricken areas this time exceeded 100,000 square kilometers.