Why nature turns vicious?

I am sure all of us are near-optimally informed of the momentous grief that Japan is struck with at present. As widespread scathe dominates, it feels if human life has minuscule value in the ample eyes of Mother Nature. We understand that our lives are directed by a set of unconquerable rules that are yet to be explored in totality, but how, why and when nature decides to act aghast against us, remains an apprehension of extreme befuddlement.

We, unknowingly, kill a lot of living creatures daily that harbor our bodies without a voluntary attempt (the medicated shampoos, antibacterial drugs, scavenger cells in our tissues which are programmed to kill a lot of extrinsic organisms etc), the question is, whether we also hold the same importance in the eye of Mother Nature? Are we chosen to exist in the world or do we just exist? What is the law of nature regarding existential reality of humans? What forces the Nature, which supplies the untiring gust of pure oxygen in our alveoli, blesses us with purest water unconditionally (60% of our bodies are made of water), gives us luscious fruits and eatables to eat, to turn a cold-blooded slayer? Is the law of harmony experiencing the draught of some missing codes, causing the marauding mayhem?

I have a genuine doubt, which I am sure; a lot of people must have had in their lives. Why aren’t we rendered disease-free in our lives? Why the constant fear of succumbing to little known syndromes and greatly known killer illnesses loops around? Who gets the thrill when we suffer? And what is achieved by this suffering? What remains unfilled in the occult equations which require the presence of sequential array of tragedies in human life? We oppose active euthanasia but we are victims of the same? Would you ever opt to put some slaughtering fungus in the succulent roots of your plant and then watch it wilting and dying? Who is better in the present understanding; a modern day thinking human or Mother Nature? Would exploring further in the milieu of Mother Nature and its laws is going to help us in understanding the significance of our existence?