Disaster. Often involving a perfectly good pie being unintentionally discarded or rendered unconsumable. Can be used for other disasters also, in which the pie becomes a metaphor, or the pie prefix is substituded for the appropriate noun. Disaster may be small, medium or large.
A thousand curses on the man responsible for this pietastrophy, leaving me hungry in the late afternoon.
Looks like a bit of a pietastrophy down the front of her blouse there.
Fuck, one of my mam's has got burnt by the iron, what a pietastrophy.