There’s no location in the world more vulnerable to tropical cyclones than India and Bangladesh. Of the 10 deadliest tropical cyclones in the world 8 have struck India, Bangladesh, or Myanmar. The Bay of Bengal is particularly susceptible to severe storm surge and vast stretches of densely populated and low lying coastline make the potential loss of life from cyclones quite high.
With any luck an eyewall replacement cycle may weaken the storm (currently a category 5 per the JTWC) prior to landfall but it appears the damage in terms of storm surge may have already been done. Given the storm’s size and current strength the storm surge will be devastating.
If there’s any good news it’s that Cyclone Phailin will be making landfall in an area not as low lying as the 1999 cyclone that struck India (which was closer to Calcutta). The very best information on Phailin can be found on Jeff Masters’ blog.