Ahmedabad: A woman with two children apparently died of sewer gas asphyxiation in Ramol area of the city. The incident took place when family was sleeping at night. The gas entered in house through bathroom sink and left 30-year-old Shemaben, her daughters Sangeeta and Lalita dead. Man and 4-month-old boy have been rescued. Ramol Police has filed case and carried the investigation further.