Four people were killed and four others injured Saturday night after scaffolding at a building construction site in south China's Guangzhou City, Guangdong Province, collapsed, a provincial government spokesman said Sunday. The accident occurred at 10:30 p.m. Saturday at the Huahuashijie construction site, South Aoti Road, Tianhe District. A witness said the scaffolding started collapsing from the third floor. The injured were rushed to hospital and an investigation into the cause of the accident is underway, Xinhua reported.