Five pilgrims were killed and nine others were injured after the vehicle in which they were travelling hit a roundabout on Tiruchendur Road here in the early hours of Sunday.
Superintendent of Police M. Durai said after losing control of the vehicle, the driver slammed on the brakes, but the vehicle skidded in the rain before hitting the structure that had no lights.
The pilgrims were proceeding to Tiruchendur from Chekkipatti in Melur taluk of Madurai district.
S. Muruganandam (40), B. Sivasankari (3), and Vasantha (60), wife of Sethuraman, died on the spot, and Anandhi (30), wife of Muruganandam, and Eswari (35), wife of Vellaiappan, died in hospital.
Mr. Durai said the injured were admitted to Tuticorin Government Hospital, where the condition of one of them was critical.
Tuticorin South police have filed a case under Section 304 (a) of the Indian Penal Code.