Heavy overnight rain on Thursday night left Chennai crippled. Streets in many parts of city, especially the coastal regions, are waterlogged. People can be seen wading through waist-high water, pushing along vehicles. Water has also entered several homes. Schools and colleges remain closed for the fourth day today. Even IT companies have been asked to remain shut. The situation has brought back memories of the 2015 floods, as well as raised questions on the work done by the state administration to improve drainage.