root knocker
Slang term used by emergency services personnel (esp. in the southern U.S.) used to describe a particulary violent vehicular collision, typically with horrendous injuries &/or fatalities.
EMT #1: Last night's root knocker had two pinned in one car and a crispy critter in the other; we had to use the Jaws of Life to pry their drunk asses out. We cut Sir Crispie out later.
EMT#2: I heard. (pause) Where do you want to go for lunch? I suddenly have a hankerin' for Bar-B-Q.
EMT#2: I heard. (pause) Where do you want to go for lunch? I suddenly have a hankerin' for Bar-B-Q.