About 400 workers at Taiwan-invested Hong Fu Vietnam Footwear Company in the central city of Thanh Hoa were hospitalized on Thursday for treatment for poisoning after drinking water at their firm. The mass poisoning began early the same day when many workers showed symptoms of poisoning, such as dizziness, belly pains, vomiting, and fainting. They had drunk water at the company not long before. The company had to call the provincial Department of Health for assistance and take the victims to some hospitals in the city, including Hop Luc General Hospital, when the number of workers experienced the symptoms increased rapidly. Many of the poisoned workers had to lie on the corridors and the ground of Hop Luc, as the infirmary became overloaded with so many people admitted at the same time. After receiving detoxification and intensive care, a number of patients recovered and were discharged from the hospitals in the evening the same day. Many others who had been in a coma were getting better but they needed to stay in the hospitals for further treatment, doctors said. The provincial health department has taken samples of the water for testing, and it has also rejected an assumption that someone had intentionally poisoned the workers.  Hong Fu Vietnam is a joint venture with Taiwan that produces shoes for export. The company began operation in 2011, employing more than 10,000 workers. A similar case happened at the company in March 2011, with nearly 300 workers hospitalized for food poisoning after lunch.Like us on Facebook or follow us on Twitter to get the latest news about Vietnam!