The government of Bangladesh is desperately trying to evacuate millions of people to avoid repeating the disaster of 1970. Tropical Cyclone Sidr, at the top of category 4 is much stronger than the 1970 storm that killed at least half a million people, however. The front edge of its furious winds is just beginning to reach land now.

Instead of weakening as earlier forecasts, Sidr has strengthened to the top of category 4 according to satellite estimates of its strength. No actual measurements of wind speeds have been done. For an excellent explanation of the meteorological aspects of Sidr, please read Alefnot's outstanding diary.

The Ganges delta is one of the most densely populated places on the planet. It is also one of the poorest. It is also flat and barely above sea level. For these reasons, it is subject to devastating floods and enormous death tolls.

One of the worst natural disasters in history occurred in the Ganges delta.

In November 1970, the deadliest tropical cyclone of the twentieth century hit the Ganges Delta region. The 1970 Bhola cyclone killed 500,000 people (official death toll), with another 100,000 missing. The Guinness Book of World Records estimated the total loss of human life from the Bhola cyclone at 1,000,000 - [1] Another cyclone hit the delta in 1991, killing about 138,000 people—see 1991 Bangladesh Cyclone.

Better preparation and better evacuation will save lives but cyclone Sidr has been at major hurricane strength for over 3 days. It has developed 40 foot high waves according to US Navy measurements. I suspect that the the largest waves are even higher, based on similar storms in the Gulf of Mexico. Sidr's foreward speed is increasing as it approaches land further builing the storm surge. Even the best preparation may not be enough to save lives.

Millions of people will be fighting for their lives over the next day as the storm moves inland. May our thoughts and prayers be with them.