A police officer searches for people trapped under a house destroyed by a tornado at Nanfeng Village of Sanduo Township in Gaoyou City, east China's Jiangsu Province, July 7, 2013. A tornado hit Gaoyou around 4:40 p.m. Sunday, striking houses of more than 400 families and hurting over 50 people, seven of whom were severely wounded. (Xinhua/Wang Zhuo)

A man clears a house destroyed by a tornado at Nanfeng Village of Sanduo Township in Gaoyou City, east China's Jiangsu Province, July 7, 2013. A tornado hit Gaoyou around 4:40 p.m. Sunday, striking houses of more than 400 families and hurting over 50 people, seven of whom were severely wounded. (Xinhua/Wang Zhuo)

People walk past a house destroyed by a tornado at Nanfeng Village of Sanduo Township in Gaoyou City, east China's Jiangsu Province, July 7, 2013. A tornado hit Gaoyou around 4:40 p.m. Sunday, striking houses of more than 400 families and hurting over 50 people, seven of whom were severely wounded. (Xinhua/Wang Zhuo)

A nurse provides medical service to people hurt in a tornado in Gaoyou City, east China's Jiangsu Province, July 7, 2013. A tornado hit Gaoyou around 4:40 p.m. Sunday, striking houses of more than 400 families and hurting over 50 people, seven of whom were severely wounded. (Xinhua/Wang Zhuo)