DEHRADUN: A mother and her two sons died after inhaling toxic gas trapped inside a long-closed water tank in the basement of their house in Manpur Paschim village in the Gaulapar area of Haldwani on Tuesday night, police said.
The deceased were identified as Saraswati Devi (55), her elder son Dharmendra Bisht (40) and younger son Khushal Bisht. Neighbours rushed the three, who had fallen unconscious, to Dr Sushila Tiwari Government Hospital, where doctors declared them dead.
The incident occurred while the family was removing shuttering from the slab of a water tank built in the basement. Officials suspect gas had accumulated inside the sealed space as it had remained closed for a long period.
According to preliminary accounts, one family member began suffocating after approaching or entering the tank area. The others went down one after another in an attempt to rescue him but were also overcome by the fumes. Residents later pulled all three out and took them to hospital.
Police rushed to the spot after receiving a call on the 112 emergency helpline. A team from Chorgalia police station, along with local residents, shifted the victims to hospital. Police and civil administration officials later inspected the site and launched an inquiry.
Sub-Divisional Magistrate Monika Arya said the deaths appeared to have been caused by poisonous gas that had accumulated inside the tank in the poorly ventilated basement. However, she said the nature and concentration of the gas would be confirmed only after a detailed investigation.
The authorities have not yet disclosed whether forensic or technical teams collected air samples from the tank. Police are examining the circumstances surrounding the incident and whether adequate safety measures were in place while the shuttering was being removed.
City Superintendent of Police Manoj Katyal urged people not to enter closed water tanks, septic tanks or basements without protective equipment, proper ventilation and checks for oxygen levels. He warned that confined spaces can quickly turn fatal because of oxygen depletion or the build-up of hazardous gases.