Some people do not believe there is a God to begin with. I don't want to go there since believing there is God and afterlife is more spiritual than argumentative, not that you can not debate it but it is not related to this thread. I think Capo is asking If you already believe in God now how you justify all these deaths and he says it is a very bad thing if God has done such a thing.
I say it really depends on how you look at it. If you are very self centered and only think about humans then it is a very bad thing that has happened. But you also have to remember that God has created the Earth and for Earth to evolve all these activities are necessary. It is like a tooth that when it falls all the germs on it die too. But a child needs this process in order to grow up.
God has created everything and he keeps balance in everything. Humans on the other hand try to break this balance to favor them and this would eventually give them trouble like all these greenhouse gases that they produce. God is not our nanny; he has given us brain to use. We now can foresee tornados. Maybe one day we are able to predict earthquakes too. You know, animals can feel it like 5 minutes or so earlier to escape from the troubled area. You have to blame yourself really and not God. If there is a God his fairness requires him to judge us based on opportunities and time and resources that we've had so we should try to do our best and not worry about the fairness of our condition.