Four people lost their lives after entering a sewage tank to clean it in a house located in Secarakudy area of the Thoothukudi district on Thursday.
According to Superintendent of Police, SP Jayakumar the four people died probably due to the poisonous gases they inhaled after entering the tank.
Two people, employed by the house owner, had first entered the tank for cleaning but when they did not come out for long, two more people had entered the tank.
After being informed about the incident, Sekarakudy police and Pudukkottai fire departments have started an inquiry into the matter.
Subsequently, SP Jayakumar also inspected the site and investigation is underway.