Protective covering, not ancient wall, collapsed

The collapsed part of an ancient city wall in Xi'an, Shaanxi province was a protective structure covering the original wall, not the cultural heritage relic itself, and restoration plans are being drafted, experts said.

The wall, located in the Xincheng district of Xi'an, the capital of Northwest China's Shaanxi province, dates to the Ming Dynasty (1368-1644). The collapse occurred about 9:30 am on Saturday, leaving four people injured and damaging a bus and three cars, according to local authorities.

The wall is listed as one of Shaanxi's major cultural relics. It protected the residence of Zhu Shuang, the second son of Zhu Yuanzhang, the first emperor of Ming Dynasty, and is not part of the Xi'an Circumvallation, the largest and best preserved ancient city wall in China and a well-known tourist destination.

The injured people were rushed to a hospital for treatment. Representatives of provincial and city government departments were dispatched to the scene on Saturday, and a task force was set up to handle the response to the accident and investigate its cause.

Xi'an and Shaanxi cultural heritage protection departments arranged for experts to inspect the collapsed section of wall and draft plans for its restoration and reinforcement. Cleanup of the site is underway.

Chen Ping, a professor at Xi'an University of Architecture and Technology, said the collapse was caused by persistent rainfall in Xi'an in recent days and the collapsed section is 20 meters of a 130-meter covering structure that was built from 2007 and 2011 to protect the original ancient city wall. The original rammed earth of the cultural relic was not destroyed.

Restoration of the wall won't be a complex project and could be done by using the ancient method of making rammed earth, said Wang Xiaoyong, an assistant researcher at Shaanxi Academy of Social Sciences.

He said it's not easy to protect a more than 600-year-old wall because of weathering. The wall has been found vulnerable to rainfall, and restoration and consolidation were being carried out before the collapse. But the downpour had been too heavy and frequent in recent days.

"The incident is a warning that cultural heritage relics need more frequent examination and restoration, even though some of them seem to be complete and solid," Wang said, adding that other parts of this wall should be inspected in a timely manner to prevent another incident.