Rudrapur, July 22 -- A 65-year-old woman and her two sons died of suspected asphyxiation after entering a newly constructed underground water tank one after another in an apparent rescue attempt at their home in Haldwani's Gaulapar area on Tuesday evening, police said. A fourth man who entered the tank to save them also lost consciousness but survived.

However, the exact cause of death will be confirmed after the postmortem, officers said.

Police said the incident occurred when 46-year-old Dharmendra Bisht entered the underground tank at his home to dismantle its shuttering using a ladder. When he did not return for some time, his younger brother, Khushal Singh, 40, entered the tank to rescue him but also lost consciousness. Their mothe...