Rescuers use life detector to search for survivors in the quake-hit town of Muping, Baoxing County in southwest China's Sichuan Province, April 22, 2013. A strong quake jolted the county on the morning of April 20. Rescuers in disaster areas are trying their best to grasp the "golden time" of 72 hours after the quake to save as many people as possible. (Xinhua/Liu Chan)

Rescuers use life detector to search for survivors in the quake-hit town of Muping, Baoxing County in southwest China's Sichuan Province, April 22, 2013. A strong quake jolted the county on the morning of April 20. Rescuers in disaster areas are trying their best to grasp the "golden time" of 72 hours after the quake to save as many people as possible. (Xinhua/Liu Chan)

Rescuers carry an injured person in the quake-hit town of Muping, Baoxing County in southwest China's Sichuan Province, April 22, 2013. A strong quake jolted the county on the morning of April 20. Rescuers in disaster areas are trying their best to grasp the "golden time" of 72 hours after the quake to save as many people as possible. (Xinhua/Liu Chan)