China Exclusive: Shanghai liquid ammonia leak kills 15 SHANGHAI, Aug. 31 (Xinhua) -- Fifteen people were confirmed dead and 25 others injured, five critically, after a liquid ammonia leak at a refrigeration unit in Shanghai on Saturday, local authorities said. The accident took place at around 10:50 a.m. in a factory at Shanghai Weng's Cold Storage Industrial Co., Ltd. in Baoshan District, the municipal government said in an official statement. Rescue work has concluded and all the injured have been rushed to hospitals. Five are in critical condition, the statement said. Following the leak, a pungent odor was detected in the air when a Xinhua reporter arrived at the location. Blue and white warning tape was set up and ten firefighters in orange uniforms were seen entering the guarded factory. A chief firefighter told Xinhua that there were no open flames after the leak, so the team carried out rescue work immediately and closed down valves that are suspected of having leaked the chemical. It smelled much worse than smoke from a fire. I sprawled on the ground and could not speak. Then my consciousness dwindled," said Gu Qijue, who was injured in the incident and is receiving treatment at Dachang Hospital in Baoshan District. Gu told Xinhua that she was in a dormitory area on the factory's fourth floor when she smelled a strong odor. She was rescued by firefighters and saved after medical treatment. Baoshan District's environmental authorities have sent environmental monitoring vehicles to test the impact of the leak. Initial test results show that odors reported early in the morning by nearby residents were unrelated to the leak, and no pollution was detected as of 5 p.m., according to an official statement. The liquid ammonia was used in food refrigeration units at Shanghai Weng's Cold Storage Industrial Co., Ltd., which is engaged in the import,export, storage, processing and sale of seafood. Liquid ammonia is a colorless liquid frequently used in industrial sterilization and refrigeration processes. The corrosive and volatile chemical may cause suffocation after heavy inhalation. As of 5 p.m., local authorities were still investigating the cause of the accident. Dachang Hospital in Baoshan District received 35 victims but 13 died on their way, according to the hospital's spokesperson. The leaked liquid ammonia could be the cause of death, said Guo An, director of the hospital's medical section. Nurses said a pungent odor filled the air when the patients arrived. "I was awakened by a harsh smell," said Li Qiufen, a hospitalized worker. I could not breathe. I stumbled out of the room and found odor coming from the workshop. There was clamor and chaos. There was no place to hide. I rolled on the ground, choking," said another injured worker surnamed Wang. The majority of workers are women from neighboring provinces. Many came to Shanghai in groups and have worked in the company for only half a month.