a quick drop and a sudden stop

(idiomatic) A fall to one’s death, especially by hanging.

Example: 2005 January 8, “Bookman”, (Google group): Clarke Survives Tsunamis:
  > But, yeah, the death penalty is a little stiff just for pretentious writing.
> Punning now… it’d be a capital idea, there.
Let’s not start _that_ row. Give it a quick drop and a sudden stop, rather than letting them hang…
2006, John Hirchak, Ghosts of Old Wilmington, page 27 (The History Press; ISBN 1596291508, 9781596291508):
  If you were lucky enough to survive all this lunacy, you always risked capture. There your story would end with a quick drop and a sudden stop, for piracy was punishable by hanging.