At least 17 people have been killed after Typhoon Rammasun swept across southern China.More than 5.5 million people were affected in the island province of Hainan and Guangxi Zhuang Autonomous Region by the typhoon.Rammasun destroyed 37,000 houses and 468,500 hectares of crops, causing economic losses worth more than 26.5 billion yuan ($4.3 billion) in Hainan.It is the strongest typhoon experienced by southern China since the 1973 typhoon season, the country's Meteorological Administration said.