By far the worst was the enormous surge that killed at least 300,000 people and possibly as many as a million in Bangladesh – then still East Pakistan – on Nov. 13, 1970. That tidal wave was triggered by an earlier cyclone in the Bay of Bengal.
The point is that those 100,000 deaths in Burma / Myanmar could have prevented by prompt evacuation of those folks.
Bangladesh/East Pakistan and the region in that area used to suffer enormous numbers of deaths. Then radar and satellite detection systems were installed and the massive deaths were reduced by allowing evacuation with the timely warnings.