Lounge window shattered this morning, nothing's touched it! window fitter says he's never seen anything like it and has put it down to the heat wave this week. Fortunately the outside glass is intact so the house is weather tight.

 Black MY2013 SD4 GS Auto, Wood Company Armrest, Freel2 sticker.
Gone MY2010 Freelander 2 Manual TD4.e S, Alaska White.

a inside pain would not have go hot enough to shatter, the frame might have swelled or the wife let the hoover fall  Former Mod/Member, with the most post & Chicken George Arch nemesis

It's a mystery how it's happened, nobody was in the room this morning. Black MY2013 SD4 GS Auto, Wood Company Armrest, Freel2 sticker.
Gone MY2010 Freelander 2 Manual TD4.e S, Alaska White.

Had something similar a few years back. Conservatory roof (double glass) inner pane went while we were out shopping - also on a hot summer's day - blew the fragments to the floor, shredding the roller shade along with the cushion covers on the seat below. Had my wife been sitting reading in the chair at the time (as she often did) she would, without doubt, been seriously injured. The conservatory firm put it down to a 'manufacturing flaw in the pane - a small fragment of silica crystal in the glass and a manufacturing fault' - and that they had only seen it happen once before (which I doubted)…..they replaced the pane (but not the damaged items!). Sadly my lass is no longer here, but from then on she was always hesitant to sit under that area of the conservatory again.

Glass is a funny thing I've seen on TV how some stained glass from hundreds of years ago slowly drips it never really sets 100%,like I say weird stuff.

I remember chemistry at school. Teacher said glass is a super cooled liquid. Bit like really thick gravy. Looks and feels solid. Then after a long time window glass gets thicker at the bottom as the glass slowly moves down the window due to gravity. Black MY2013 SD4 GS Auto, Wood Company Armrest, Freel2 sticker.
Gone MY2010 Freelander 2 Manual TD4.e S, Alaska White.

The same happens with soldered electrical joints, it is called 'cold flow', over time the solder flows and sags due to gravity, this leads to electrical connections becoming loose, never solder wires before screwing them into a terminal

Friend had this in their fairly new build. Builders put it down to settlement in the house and the window being flexed beyond its tolerances. FL2 TD4 GS 60 reg Facelift - so many issues
2019 DS. Terribly unreliable.
Sold DS for a 2021 Mitsubishi Outlander PHEV. Fingers crossed....
Sold Outlander for a 2014 SD4 SE Tech because I’m mental
Now greatly regret selling the Outlander. MPG of the FL2 is atrocious and so are the fuel bills. Fun though 😎
Couldn’t afford the fuel bills so back to an older Mitsubishi Outlander PHEV. Significantly better than I remembered it to be…

My end door glass is exactly the same,pure coincidence I am sure but I was strimming nearby at the time!

We has this in the office a few years back - there are glass lined walk ways (very thick glass) and a number of them suddenly shattered over a period of time. It was put down to a fault in the manufacturing / hardening.

Glass being a liquid and made from sand it very much depends on the filtering process at the manufacture stage, the sand will contain impurities, iron ore, grains of rock with higher melting point etc, normally when the glass is made this isn't a problem as the skin is not under tension. When toughened the skin is under tension the inside is still a liquid and these impurities float and move with the heating and cooling, should one touch the skin and it being sharp enough the surface shatters, there are a few panoramic car roofs that also suffer. Car side windows and patio doors can bend considerably more than a standard pane of glass but the application of a sharp point and it lets go, if you need to break a car side window, don't try to kick it in just ask the OH to scrape the rock on her engagement ring across it and give it a rap. my PC is slightly to the right of Genghis
2012 HSE SD4 In Orkney Grey now gone, best car ever.