When a good plan turns into a total disaster. A combination of a shabang and a debacle.
"Man I'm pissed. We were all having a nice picnic in the park until a PitBull stole our rasberries. "It was a total shebacle"
A shenanigan that turns into a debacle. Mischievous or playful activity that quickly becomes disastrous.
This bachelorette party quickly became a shebacle.