Five persons, including a woman, died of asphyxiation inside a newly constructed septic tank at Durgi village in Odisha’s Rayagada district on Sunday morning.The woman, Rashmita Kadraka, was the first to suffer asphyxiation inside the tank. Five others who entered the tank to rescue her also suffered the same fate. One of them is battling for life at the Christian Hospital in Bissamcuttack.Roof brokenVillagers had to use an excavator to break down the roof of the underground tank to rescue the six unconscious persons. All of them were shifted to the Christian Hospital, where five were declared dead.The mishap occurred around 9.30 a.m. at a house at Paika Street in Durgi village. The woman was the first to enter the tank and fell unconscious after inhaling poisonous gases formed inside the closed tank. When she did not come out, a mason entered the tank to rescue her and become a victim of asphyxiation.To rescue the two, four youths of the village then entered the tank. When the six persons did not come out, the villagers used an excavator to break open the roof of the tank to rescue them. The unconscious persons were immediately taken to hospital, but five of them could not be saved.The local police have sent the bodies of the five deceased for autopsy and started investigations.