How is that relevant? The social sciences are focused on understanding the patterns of social causation and gleaning certain truths from them.
The "random events" you are referring to are outliers and exceptions to the rule. Things are not as unpredictable as you seem to think. Most of those events still have effect natural and/or social phenomena in predictable ways. houses didn't get torn apart in Katrina in a manner inconsistent with the laws of physics. The societal chaos and political fallout from Katrina were consistent with certain theories of social causation in various different fields.
Also, you are still negating all thought and all attempts to understand the truth, weather in a field of hard science or social science. Undermining the truth is not a credible argument.
