Four persons died of asphyxiation after inhaling methane gas during "maintenance work" at a sewage tank in the Hyundai car factory at Irrungatukottai near here, fire service officials said.A person fell ill and has been admitted to a private hospital in Chennai, and his condition was stated to be out of danger, they said.The incident occurred at the second stage plant last night when the five contract employees were attempting to clean the sewage tank, which was used to store wastes of paints and other chemical materials, the officials said.Initial reports this morning said there was a fire accident in the plant, but later the fire service clarified that it was an incident of asphyxiation.Fire service officials attributed the mishap to "neglect" in undertaking maintenance work. The deceased include a site engineer and an electrician.Hyundai Motor has announced an ex-gratia payment of Rs 2 lakh each to the deceased.
