as c said, the mystery isn't why they fell but why they didn't fall.
to do: nail box back together and attach to wall with several hundred goodly-length wood screws.
first though I have to figure out why my audio-recording software is acting up. and then to flesh out the bass line that is becoming interesting at the rate of one measure per day. it would probably go quicker if I actually knew anything about music but as is my choices after the first note are pretty much unlimited which makes it all the more difficult.