Several parts of the city including the downtown and outskirts had witnessed heavy rainfall and the rainfall had inundated important roads in the city.
The Chief Minister had declared a public holiday on Wednesday and he appealed to the people not to exit their residences until everything gets into normalcy.
Weather experts say that the depression would get intensified into a cyclonic storm over the next 48 hours and will cross between Karaikal and Mahabalipuram around the noon hours of November 25.
There is a possibility of heavy rain with thunder and lightning in 9 districts in Tamil
Nadu for the next 24 hours, reported The Chennai Meteorological Department.
Prime Minister Modi said, "Pained by the loss of lives due to a landslide in Rajamalai, Idukki. In this hour of grief, my thoughts are with the bereaved families."