At least 15 people died after a compound wall collapsed and damaged three houses in Nadoor Kannappan Layout in Mettupalayam on Monday morning following heavy rain in the region.
Rescue operation is currently underway.
Tamil Nadu government has announced compensation of Rs 4 lakh each to families of those who have lost their lives.
Additionally, a flood alert has been issued to people living on the banks of river Bhavani in the Erode district of Tamil Nadu as a dam built across it has surplussed in the wake of copious rains in catchment areas.
The dam has filled up for the sixth time this year following heavy rains in the catchment areas in hilly Nilgiris district and Mettupalayam in neighbouring Coimbatore district.
Schools and colleges will remain shut in Chennai and Tuticorin, Tiruvallur and Kancheepuram, where large parts are flooded.
Widespread rain is expected across coastal Tamil Nadu due to a cyclonic circulation near Comorin on the Indian Ocean, according to the weather office.
The state government says it is well-prepared and there is no need to panic. In Chennai, the state government has set up 176 relief centres. Boats have been kept ready to evacuate people if required, assured the Chennai Corporation. Over 600 water pumps will be used to remove water-logging in low-lying areas.
— With inputs from agencies