"As they passed by in the morning, they saw the fig tree withered away to its roots. And Peter remembered and said to him, “Rabbi, look! The fig tree that you cursed has withered.”
The event isn't the issue. The event is often the by-product of the issue. When we concentrate on an "event" or "happening" we miss the larger, and arguably the more important matter, which is what caused the "event" to occur in the first place. Logic dictates that if you want to prevent fruit from growing on a tree ever again, pull it up by the root. What's the root cause of your problem or the issue? Regarding Ferguson, what is the underlying mindset that allows these tragic events from occurring with such frightening predictability?
Rarely, what we see on the surface is the cause. It's usually just the manifestation of something deeper, hidden from sight. Resolve it, solve your problem.