At a very high level, you are technically correct - existence is inherently risky and, try as we might, we can't always prevent disaster from striking. Disaster

At a very high level, you are technically correct - existence is inherently risky and, try as we might, we can't always prevent disaster from striking. Disaster will strike again, somewhere. At a more macro level, we certainly do understand relative risks of specific areas after interacting with them long enough. We begin to get a better picture of what makes one flood plain significantly more dangerous than another. There are instances where things like this can be avoided, or at least mitigated to a certain degree.