The rains are the heaviest in 100 years and are likely an effect of climate change.
Hundreds of thousands of people in the big city now face acute short supply of water, electricity and food. Many have lost both their homes and their income. In most buildings in Chennai the water level has raised above the first floor and one of the biggest problems is also the lack of toilets.
Many construction sites have been completely ruined and cement shops fully collapsed. There is a lack of material to rebuild what has been destroyed.
Leaders and members of the construction workers' union AIKTMS have been working intensely to reach out to people in the worst affected areas in Chennai. Using rescue boats the union have been able to rescue people bring them to safety. The union has also set up a relief fund and collected money from members, leaders and employers to be able to buy bread packets, clothes, blankets and other necessities to flood victims.
The need for food, cooking materials and clean water is urgent according to the union, which is demanding the central and state governments to do more to ensure the safety of people.