TIRUCHY: Three construction workers died of suffocation while working inside a newly built septic tank at a house under construction at Senthurai in Ariyalur district on Friday.

The police identified the deceased as Dinakaran (60), of Alivalam in Tiruvarur; Baskar (45) of Srinivasapuram in Tiruvarur; and Ramachandran from Senthurai in Ariyalur.

According to the police, M Subramanian (61), a resident of Gandhi Nagar in Senthurai, was constructing a house at Vallalar Nagar on the Sendurai-Udayarpalayam main road. A septic tank with a height of 12 feet and a depth of 8 feet had been constructed.

On Friday, Dinakaran and Baskar were removing the wooden boards and poles inside the tank used for support while constructing the tank, while Ramachandran was helping them from outside.

Suddenly, both Dinakaran and Baskar collapsed. Ramachandran found the duo lying unconscious and entered the tank to rescue them. But he too experienced breathing difficulties and fell unconscious.

On receiving information, the building owner Subramanian rushed to the spot and alerted the Senthurai police and the fire and rescue personnel. All three were rushed to the Senthurai GH where the doctors declared them dead. Subsequently, the bodies were sent to Ariyalur Medical College Hospital for the postmortem.

The police questioned Subramanian. The fact that the septic tank was newly built and yet to be used raised eyebrows about the death. The initial investigation found that the septic tank was closed for more than 20 days after construction for curing and the police also found that there was some foul smell emanating from it, which might have caused suffocation resulting in death. A detailed investigation is under way, the police said.

It may be noted that on September 2, exactly a month back, two workers who were involved in cleaning a septic tank in Tiruchy asphyxiated.