Photo taken on Nov. 27, 2012 shows a bus collision scene in Wan Chai, south China's Hong Kong. At least 40 people were injured in a traffic accident involving three buses in Hong Kong on Tuesday evening, local authorities said. (Xinhua/Lo Ping Fai)

Rescuers work at a bus collision scene in Wan Chai, south China's Hong Kong, Nov. 27, 2012. At least 40 people were injured in a traffic accident involving three buses in Hong Kong on Tuesday evening, local authorities said. (Xinhua/Liu Yongdong)

Rescuers save an injured passenger at a bus collision scene in Wan Chai, south China's Hong Kong, Nov. 27, 2012. At least 40 people were injured in a traffic accident involving three buses in Hong Kong on Tuesday evening, local authorities said. (Xinhua/Lo Ping Fai)