A cyclone which barrelled through India"s southern coast earlier this week has left Chennai city flooded and struggling to return to normal. Authorities are trying to clear rainwater from homes and streets in the city"s suburbs. Some residents say they are unable to access basic necessities and are experiencing frequent power cuts. At least 18 people have died in Tamil Nadu state — of which Chennai is the capital — in rain-related incidents. Cyclone Michaung made landfall on Tuesday in neighbouring Andhra Pradesh state - a child was killed and heavy crop damage was reported there before the cyclone weakened into a deep depression. On Monday, about 24cm (9.4in) of rain fell on Chennai - India"s meteorological department classifies rainfall above 21cm as "extremely heavy". The heavy rains brought back memories of deadly floods in 2015 which killed more than 200 people in Chennai, one of India"s largest cities which is also an industrial hub. Experts say that many Indian cities are unprepared to deal with extreme weather events due to unchecked construction and poor urban planning. On Monday, the busy Chennai airport was shut down for a day after its runway was flooded. Dozens of trains were cancelled over the past three days. Mint newspaper reported that the economic impact of the flooding was expected to be "severe" as production was disrupted at several companies including Apple supplier Foxconn. On Thursday, municipal officials in Chennai were using equipment to pump out water from the streets in the city"s southern suburbs to allow vehicles to move. J Radhakrishnan, the commissioner of Greater Chennai Corporation, told BBC Tamil that authorities had pumped out "as much water as possible after 36 hours of continuous rain". He added that as of Wednesday night, floodwaters had receded in three-quarters of the city. Thousands of people were evacuated to relief camps over the past three days - many were rescued from their flooded homes in rubber and fibre boats. Authorities are also trying to restore supply of drinking water in some areas. Experts say that rampant construction has left little space for rainwater to drain away. "Homes are flooded whenever it rains heavily because buildings have been constructed on the swampy catchment areas of lakes and ponds in some of Chennai"s suburbs," David Manohar, an activist who studies urban flooding, told BBC Tamil. Raj Bhagat P, a geo-analytics expert, told Reuters that while better stormwater drainage systems can stem flooding, even that would not help much during "very heavy and extremely heavy rains". The Tamil Nadu government has asked for interim federal assistance of 50bn rupees ($600m; £478m) for the state. Chief Minister MK Stalin said in a post on X (formerly Twitter) that infrastructure has been "severely hit". Mr Radhakrishnan said that authorities will do a survey to identify areas where stormwater drains did not work as well as they should have. "But that is a long process. Now we are focusing on the rescue work," he said. — BBC