This morning at about five o'clock we were both awoken by a loud ... well ... cracking sound. An abrupt sound followed by a few drips of water from the shower in the en suite adjacent to our bedroom. When Sal first asked what it was, I replied that it was simply the shower head having "fallen down" (ie loosened on its hinge and swung down to hit the wall). Unconvinced, she got up to investigate.

Turns out our bathroom window has shattered. For seemingly no reason, it has completely cracked. Not in a spider-web pattern as if something had hit it - just completely shattered. Here's a photo, with the other, intact half in the picture for comparison:

shattered

If you click on this and get the big version, you'll see that there are minute cracks in the glass, some of which are large enough that you can see through them to outside.

So I've taken the day off - at 9am I'll start ringing glaziers until I find someone who can come out today to take a look at it. Hopefully they'll know what can cause this to happen! Maybe I was singing soprano in my sleep or something.