- Aftershocks hampered initial rescue efforts, officials say
- The quake had a magnitude that exceed 6.0, according to two agencies
- Housing quality, high population density, shallow epicenter contributed to death toll
The death toll has risen to 615 after Sunday's earthquake in southwest China's Yunnan province, China's state-run CCTV reported Thursday evening, citing the earthquake relief command.
The epicenter of the quake was recorded in Longtoushan Township, 23 kilometers (14 miles) southwest of Zhaotong, and tremors were felt almost 200 miles away. Hundreds of aftershocks were recorded following the initial tremor. Poor weather conditions and the aftershocks hampered rescue efforts.
It's a fairly remote, partly mountainous area. Many residents live in low-rise houses made of wood and bricks or plaster, which make them prone to collapse. The quality of the housing, along with the higher-than-average population density in the area and the relatively shallow epicenter of the quake, were said to be contributing factors in the death toll.
Some 12,000 homes were destroyed and 30,000 others damaged in Sunday's quake, according to CCTV. Tens of thousands of people have been relocated from structurally unsafe houses. Some roads were destroyed and some villages remain cut off.
The U.S. Geological Survey said the quake had a magnitude of 6.1, while the China Earthquake Networks Center reported it as a 6.5-magnitude event.
Yunnan's neighboring province, Sichuan, witnessed a magnitude 7.9 earthquake in 2008 in which at least 87,000 people died.