The sky is falling, the sky is... -crash!-
Thankfully, no one was under it when the several square foot hunks of plaster came crashing down. We hustled the kids onto the porch so that they wouldn't try to eat old damp plaster. This was Wrong and Bad and resulted in much whining and crying until we were packed up and in the car. (To be fair, it was a long weekend and they were low on sleep because they GOT UP AT 5:30)
Brother-in-law came to the rescue later, getting the rest of the creaky ceiling down safely.
Just so very random.