A man and two boys drowned in the Pappipatti kanmoi in Kailasapatti near Periyakulam in Theni district here on Thursday.
Another boy, L Rudran, 7, who had gone with the deceased to the tank was admitted to Government District Headquarters Hospital in Periyakulam in a critical condition and was later shifted to Theni Government Medical College and Hospital for further treatment.
The deceased and the survivor had visited M. Dharmaraj, 50, of Kailasapatti to attend the Muthalamman temple festival under way.
The deceased have been identified as R Panneerselvam, 25, of Thottiyapatti, Peraiyur Taluk, L Manimaran, 12, of Meelapatti, Nilakottai and B Sabari, 11, of Velan Servaikaranpatti.
The victims were retrieved by people around 4 p.m. and sent to Government Hospital in Periyakulam where they were declared dead by the doctors.