A cyclone hit the eastern Indian state of West Bengal on Monday killing at least seventeen people and forcing an estimated 80,000 people to leave their homes for safety, officials said. Authorities warned people in state capital Kolkata to stay indoors as cyclone Aila advanced towards the city of 12 million with winds up to 100 kph (60 mph). Heavy rains triggered by the storm raised river levels and burst mud embankments in West Bengal's Sundarbans Tiger Reserve, which holds thousands of people as well as the world's biggest tiger reserve. “The situation is very grave, countless families have been displaced, especially in the Sundarbans,” said Kanti Ganguly, state minister for the Sundarbans. Authorities in neighboring Bangladesh also evacuated thousands of people, mostly in Khulna district near the Sundarbans, to makeshift shelters as tidal waves triggered by the storm in the Bay of Bengal damaged thousands of houses. “It has already started hitting Bangladesh's coast, with a maximum wind speed of 90 kilometres (56 miles) per hour. We have reports that a tidal surge has inundated many coastal villages,” the Bangladeshi official said. “We have evacuated some 100,000 people to the district's cyclone shelters. Schools and colleges have been ordered to give shelter to the affected people,” he said. District chiefs in neighbouring Satkhira, Patuakhali and Bagerhat said that they evacuated another 230,000 people as tidal surge along with strong wind and heavy rains hit the coastal villages. Four people died in Kolkata in house collapses while several other deaths were reported from other parts of the state.