This image shows Indian Cyclone Phailin on Friday
Cyclone Phailin is expected to cause extensive damage in eastern India, with a storm surge that will flood low-lying areas and heavy rains and strong winds that will last for hours. Here are some details on other devastating cyclones that have formed in the Bay of Bengal:
May 2008: Cyclone Nargis hits Myanmar with a storm surge that washes up densely populated areas around the Irrawaddy River delta. Around 138,000 people died and tens of thousands of homes and other buildings were washed away. Damage to public and private assets was estimated at around $10 billion.
October 1999: A super-cyclone sweeps through Odisha in, killing at least 10,000 people and leaving an estimated 1.5 million homeless. Winds of over 250km/h (160mph) were recorded, and a devastating tidal surge drove across coastal plains.
April 1991: Nearly 139,000 people died from a cyclone that hit Bangladesh with mighty 225 kph winds and a storm surge between 6 meters and 7.6 meters.
November 1977: A devastating cyclone struck Andhra Pradesh. A total of 14,204 people were killed; however, some estimates place the loss of life at 50,000. Damage from the cyclone was placed at $498.5 million.
November 1970: A cyclone hit Bangladesh. It had winds of 224 kph and a storm surge between 6 and 10 meters. More than 300,000 people died, according to the Bangladesh disaster management and relief website.