NEW DELHI — A powerful cyclone killed more than 85 people in India and Bangladesh, flattening tens of thousands of homes and battering the metropolis of Kolkata after it roared ashore on Wednesday.

The Indian state of West Bengal bore the brunt of the storm’s fury. Two low-lying districts in the state suffered widespread destruction of homes, crops and infrastructure, while its capital, Kolkata, witnessed torrential rains and winds of up to 100 miles an hour.

At least 72 people died in West Bengal, 15 of them in Kolkata. Many were crushed by falling trees or electrocuted by downed power lines.

Cyclone Amphan left a “trail of devastation,” said Mamata Banerjee, the chief minister of West Bengal. She said she had never seen a similar disaster in the state.

A metropolis of 15 million people known for its crumbling charm, Kolkata awoke Thursday to waterlogged streets filled with debris, power outages and the sight of huge trees toppled over onto cars and buses, crumpling them like tin cans.

Goutam Pradhan spent a sleepless night on the third floor of his 35-year-old family home in Kolkata after water began flooding in from the street and the electricity went out. The howling wind shattered the upstairs windows, scattering shards of glass on his 9-year-old daughter.

“I have never seen such scenes in my entire life,” said the 47-year-old lab technician. “I was scared for my life and for my family’s life.”

The storm began over the Bay of Bengal as one of the strongest tropical cyclones ever recorded in the northern Indian Ocean. Although Amphan weakened as it approached land, it brought powerful winds, driving rain and a huge tidal surge.

About 3 million people were evacuated from their homes in India and Bangladesh ahead of the storm’s arrival. Both countries are battling rising numbers of novel coronavirus cases, and some evacuees feared they might contract the virus during hours stuck inside emergency shelters.

In Bangladesh, at least 16 people were killed and more than 55,000 homes collapsed, authorities said. The storm’s path did not bring it directly over one of the world’s most vulnerable refugee populations: Instead, it passed northwest of Cox’s Bazar, which meant that about a million Rohingya living in crowded camps were spared its worst effects.

Indian authorities said that it would take time to reach a full assessment of the storm’s impact. About 500,000 people in West Bengal were still in emergency shelters, said S.N. Pradhan of the National Disaster Response Force, because roads were impassable or their homes were damaged.

The loss of dwellings and crops, coming after two months of a nationwide lockdown that has left millions of Indians without an income, risks pushing those impacted by the storm into destitution.

On Thursday, Amphan had dissipated as it moved north but was still unloading torrential rainfall that could exceed a foot in some areas. Flash flooding and mudslides are expected to threaten parts of northeast India, northern Bangladesh, Bhutan, and northern Myanmar into the weekend.

Deepanjana Dey, a journalist from Kolkata, witnessed the impact of the cyclone in one of the worst-hit districts, South 24 Parganas. It sits directly on the Bay of Bengal and is home to a vast mangrove forest.

“The mud houses have been flattened, there are cable wires and fallen trees everywhere,” said Dey, 33. “It is a devastating sight.”

Tania Dutta and Niha Masih in New Delhi; Azad Majumder in Dhaka, Bangladesh; and Jason Samenow in Washington contributed to this report.