Night before last I heard some strange POP sound from the vicinity of the laundry room. I investigated and here's what I found:
You can click on the picture to see a close up of the damage.
Of course, I was initially worried that it was someone trying to break in, but inspection that evening and re-inspection during the day yesterday confirmed that nope, no way this was caused by anything or anyone hitting the window, this glass just broke all on its own. It's just the exterior pane of the double-pane window that broke, but the screen is completely undamaged, and it's too far away from the window and much too taught for anything to have gotten through and broken this window without damaging the screen in some way. We poked and pushed on the screen and tried everything to see if we could get to the window without damaging the screen, and it just wasn't happening.
I did at least find out from the PO's where they got the windows (edited - see note at end), so I'm going to stop by the store where they got them from today while running errands and see if they can tell me if the pane can be replaced (since I'm told that on some double-pane vinyl windows they can't) or if I have to replace the whole blasted window.
Grrrrrrrr. What I wouldn't give to have the original windows and some good storms. Instead, I can foresee that within the next decade or so we'll likely be replacing the windows as one by one they fail in some way that, unlike a good wood window, can't be replaced.
Edited note: The store gave me the number for the manufacturer of these windows and it's not yet been confirmed since I wasn't at home to give them the sticker info off the windows, but it sounds like they are going to be covered under warranty even though I'm not the one who installed them and it's been 8 or 9 years since they were installed. Nothing will stop me from wishing I had the original wood windows, but if the manufacturer provides the kind of customer service that so far it seems that they might, I'll at least not blast them by Googleable name.