A powerful cyclone lashed India and Bangladesh forcing the evacuation of nearly three million people.
Winds of more than 160 kilometres per hour caused extensive damage, uprooting trees and electricity poles.
Seawater has been swept inland and flooding is feared in Kolkata.
One person died in Bangladesh where 2.4 million people living on the coastline were moved to safer areas.
India evacuated more than 400,000 people, in particular in the eastern state of West Bengal and in the neighbouring region of Odisha.
The cyclone, named Amphan, is the biggest one to have originated in the Gulf of Bengal since 1999.
Evacuation operations were made even more challenging by coronavirus, as some shelters were already hosting COVID-19 patients and migrant workers.
Masks and hand-sanitisers were hastily added to the emergency items stocked in shelters, though a vast amount of people got their protective masks with them while being evacuated.
Some residents, however, decided to remain home, fearing they would catch coronavirus at the shelters.
"We heard that the 'high-pressure' shelter near the police station is packed with people. There is no more space there. My neighbours and my family did not go there for fear of the coronavirus," Bangladeshi villager Sulata Munda told AFP news agency.
In Bangladesh's Sathira district, local chief government administrator SM Mostafa Kamal said evacuees were given food and medicine.
The cyclone struck Bangladesh's vastly-Muslim population as it was celebrating Ramadan.
The region is not new to such devastating cyclones, but some experts have pointed out that their intensity might have grown because of climate change.
Cyclone Amphan reduced its speed after reaching the cooler coastal areas and it is expected to head north-east.