There is a difference between evil caused by people and other bad things like natural disasters. Man received free will from God, and he can make good or bad choices. If God would intervene, we would no longer be free!
Why natural disasters occur, and why God does not intervene to stop the horrible evil committed by some people, remains a mystery. It is, however, never a punishment from God, who is full of love. God commiserates with those who suffer and inspires people to help each other. If we cooperate with him, then evil can never have the last word.
