The wrath of God is not a topic that falls within my modest expertise, but I could not resist linking to this excellent essay by Monseigneur Charles Pope of the Roman Catholic Archdiocese of Washington, D.C.
My summary: bad things happen, and as people drift away from worshipping God, a downward spiral of disaster and evil can overtake the populace. This is often referred to as the wrath of God, but it reflects no anger on God’s part, just a revelation of the gap between God’s goodness and the folly of men. People who love and trust the Lord experience the same physical miseries as their secular brothers, but try to see events as lessons given by a kind Father for their benefit. Ones who have no sympathy for our Creator see dire events as the “wrath of God,” a mindset which comes from within themselves.