According to police, Senthil Kumar and Praveen (19) developed breathing difficulty after they entered the septic tank at Karapakkam. While Praveen managed to get outside the tank, Kumar fell unconscious.
After the driver of a tanker hired to pump out the sewerage alerted a passerby, the Kannagi Nagar police and an ambulance reached the spot. Kumar was declared dead and Praveeen taken to a nearby hospital for treatment, police said.
Police sent Kumar’s body to the Royapettah Government Hospital for a postmortem. While the cause of the death is yet to be ascertained, they believe it could be asphyxiation.