When pressed as to why they hadn't tried to warn them about the dangerous tsunami, the UK and the US admit today that they did try frantically to warn the governments of these countrires.
The UK went so far as to get the High Commissioner in Sri Lanka and Bengal to make the most urgent phone calls he could make, but nobody took them seriously enough to actually start physically evacuating their citizens.
I'm not sure how much good public warnings would have done. These are low lying, sea level or below sea level areas with not much in the way of an effective news media for most of the people who would've been caught.