Once upon a time in a well-established urban neighborhood in the urban Southeast (aka Midtown Atlanta), there was a Killer Tree. Of course, the tree looked perfectly normal when it was a little tree, way back when the houses and streets and sidewalks were being built. It also looked like a normal tree when it was a young tree, and even as it reached middle age. It grew tall and robust, and its branches reached high and needed no pruning. The Killer Tree, in its younger days, gloried in providing shade for the house below it, for the cars that parked along the street below it, and for the children who played in the yard it shaded.
One day, however, the Killer Tree awoke from its stupor of normality and began to contemplate its situation. The Killer Tree discovered that it could not move and could not find out what was beyond its viewscape. The Killer Tree found this very frustrating.
And, lacking any other means of showing its frustration, the Killer Tree dropped a branch.
And that is the story of how the Killer Tree earned its name.