I used to live in a small town in Missouri and the Post Office was right across the street from the fire station. They had an escalating 'war' -- post office employees shooting volleys of rubber bands at the firefighters, who retaliated with fire extinguishers and so on.

One day, I was walking home and the firefighters had the water cannon of the one pumper truck trained on the front door of the Post Office for several minutes -- broke the window and flooded the whole post office.

That pretty much ended it.