Three people were killed Friday afternoon after being buried by calx powder in a smelter in south China's Guangdong Province, local authorities said Saturday. The three people were cleaning a workshop of Renhua Danxia Smelting Plant in Shaoguan City when a huge container overturned and poured more than 10 tonnes of the ashy substance on them, Xinhua reported. Their bodies were retrieved Saturday morning, said a municipal official. An investigation team was looking into the case, he added.