so many religious responses to tragedy exacerbate suffering. any explanation that blames the victims for their situation is theologically untenable, whether the language of blame is "karma" or "sin."
God did not cause the tsunami. an earthquake that was the result of some kind of natural (albeit unusual) movement of tectonic plates caused the tsunami.
so where is God in the tsunami? suffering with creation. God/spirit was with each and every living being that perished and survived the waters. God felt everything they felt: fear, agony, pain- i cannot even imagine how to complete this list of conjecture, but i do believe that God experienced the spectrum of physical and emotional suffering imposed on south asia.
i suppose some people would rather believe that God is omnipotent, capable of reaching through the cosmos to stop (or start) calamity. i find it much more compelling to believe that God is wholly benevolent, suffering with us in solidarity and compassion. when creation- and humans in particular, since we are the species that is so dang errant- bends its will toward God's will, perhaps some semblance of omnipotence is possible. the power of cooperation and communion.
so my prayers are: may the God's suffering presence be recognized by the suffering ones of this world, that they may know that the creative spirit of life is with them.