An excavator is used to search for the buried at the site of a pipeline explosion in Qingdao Development Zone, in Qingdao, east China's Shandong Province, Nov. 24, 2013. A leaking pipeline caught fire and exploded on Friday morning in Huangdao District of Qingdao. The death toll in the explosion rose to 52 and the search effort is still ongoing. [Xinhua]

A rescuer searches for the buried at the site of a pipeline explosion in Qingdao Development Zone, in Qingdao, east China's Shandong Province, Nov. 24, 2013. A leaking pipeline caught fire and exploded on Friday morning in Huangdao District of Qingdao. The death toll in the explosion rose to 52 and the search effort is still ongoing. [Xinhua]

Workers are seen at the site of a pipeline explosion in Qingdao Development Zone, in Qingdao, east China's Shandong Province, Nov. 24, 2013. A leaking pipeline caught fire and exploded on Friday morning in Qingdao. The death toll in the explosion rose to 52 and the search effort is still ongoing. [Xinhua]

Rescuers search for the buried at the site of a pipeline explosion in Qingdao Development Zone, in Qingdao, east China's Shandong Province, Nov. 24, 2013. A leaking pipeline caught fire and exploded on Friday morning in Huangdao District of Qingdao. The death toll in the explosion rose to 52 and the search effort is still ongoing. [Xinhua]

Rescuers search for the buried at the site of a pipeline explosion in Qingdao Development Zone, in Qingdao, east China's Shandong Province, Nov. 24, 2013. A leaking pipeline caught fire and exploded on Friday morning in Huangdao District of Qingdao. The death toll in the explosion rose to 52 and the search effort is still ongoing. [Xinhua]

Excavators work at the site of a pipeline explosion in Qingdao Development Zone, in Qingdao, east China's Shandong Province, Nov. 24, 2013. A leaking pipeline caught fire and exploded on Friday morning in Huangdao District of Qingdao. The death toll in the explosion rose to 52 and the search effort is still ongoing. [Xinhua]