It was Satan. He wants tsunamis to kill as many people as possible. Death means no more chances to evangelize or to get evangelized about Jesus Christ. Its win-win for him either way.

To those murderers,

I don't know who you are but I hope you know that you are FOLLOWERS OF SATAN! You are going to follow him to the lake of fire. If you think life here on earth is hell, wait till you get there. And Satan will reward you there by even oppressing you some more on top of it all. You & every single one of you who shares your messed up twisted beliefs.