Five people died and four others were injured when a tank in a processing plant in southwestern China collapsed Tuesday, officials said. Three people died at the scene and two people died en route to a hospital after the waste-water treatment tank collapsed at a cassava starch processing plant in Yunnan province, China' state-run Xinhua News Agency reported. The plant is owned by a local agricultural development company, local officials said. Xinhua said the cause of the accident was under investigation.