At least two districts - North and South 24 Parganas districts- have been the worst-hit by one of the strongest storms to hit the region in several years.
"Sarbanash hoye galo (It is a catastrophe)...Communications are disrupted," said Mamata Banerjee, who remained in her office during the storm, adding that although 5 lakh people had been evacuated, state authorities had not entirely anticipated the ferocity of the storm. With rains continuing, she said the hardest hits areas were not immediately accessible. The Chief Minister also used the word "tandav (dance of fury)" to describe the impact of the storm.
"I am sitting in the war room. My office in Nabanna is shaking. I am tackling a difficult situation on a war footing. The storm is likely to continue till midnight," Ms Banerjee said in a statement on Wednesday night.
The Kolkata airport, which remains shut, was left flooded and many structures within damaged.
In state capital Kolkata, strong winds upturned cars and felled trees and electricity poles. Parts of the city were plunged into darkness. The streets were waterlogged and trees uprooted.Kolkata and several other districts faced power outages at night, with power supply restored only late at night.
"Have been seeing visuals from West Bengal on the devastation caused by Cyclone Amphan. In this challenging hour, the entire nation stands in solidarity with West Bengal. Praying for the well-being of the people of the state. Efforts are on to ensure normalcy," PM Modi tweeted.
Amphan lay about 270 km north-northeast of Kolkata as of 5:30 am today, the weather department said. It is very likely to continue to move in that direction and weaken further into a deep depression during the next three hours and into a depression in the subsequent six hours, the Met office said.
Union Home Minister Amit Shah today said he has spoken to Ms Banerjee and Odisha Chief Minister Naveen Patnaik, assuring all help from the centre. Over one lakh people in Odisha have been moved to safer places.
Cyclone Amphan is only the second "super cyclone" to form over the Bay of Bengal since records began, and the first since 1999. Odisha was hit by a super cyclone that left nearly 10,000 dead in 1999.
"Amphan", pronounced as "Um-pun", means sky. The name was given by Thailand in 2004, years ago. The storm is being constantly tracked by Doppler Weather Radar at Visakhapatnam.
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