Way back when at a Whitby Festival I was walking up the Kyber (steep hill) when the spring lock on my concertina box sprung open and my prize Wheatstone Special anglo dropped out and started rolling down the hill. Luckily it's a heavy beast and I was able to chase after it and arrest its motion before any vehicles came up the hill (one way). Had it been something like an edeophone it would have taken a dive to catch it. Needless to say I immediately fitted extra clasp locks onto the box when I got home. BTW the instrument wasn't damaged one bit. Not bad for nearly a century old. They don't make em like that any more!