The death toll in the 11-storey building collapse went up to 30 Tuesday while 27 people have been rescued from under the debris, officials said.
Around 70 people were said to be trapped under the debris when the under-construction building collapsed Saturday evening.
Severe stench has started emanating from the debris and efforts are being made to prevent any outbreak of infection.
With occasional rains, rescue workers and relatives are praying to the rain gods to show mercy till the debris are cleared and all those trapped under it are secured.
"The rain would not only hamper the rescue work but there is also the risk of flooding the gaps under the debris risking the lives," said a person at the site.
However, the rescue of four people Tuesday after nearly three days gave the rescue team some hope.
Three people - a husband and wife and another person - were found breathing through a pipe.
The rescue team faintly heard a metallic tapping noise Tuesday morning and rescued the three.
In the evening, one more person - Vikas from Odisha - was rescued.
Relatives of the people trapped under the debris are praying for the safe rescue of their loved ones.
Meanwhile, Tamil Nadu's Public Works Department (PWD) has declared "unsafe" an adjacent 11-storey building - part of the same project.
The residential project Trust Heights was being developed by Prime Sristi Housing Pvt. Ltd. The project comprised two 11-storey blocks - The Belief and The Faith.
Most of the people trapped under the debris are said to be construction workers and some might have taken shelter in the building as it was raining at the time of the collapse, people in the area said.
Giant steel rod cutters and other equipment have been pressed into service, while sniffer dogs and sophisticated cameras are at the accident site to locate trapped people.
