I ordered a pane of toughened glass about 1.5m tall by 0.5m wide, which
I collected today intending to fit it - it's for a fixed light adjacent
to a front door.

Anyway, I got the old glass out this evening, cleaned everything up,
applied putty to the rebate and picked up the new pane... I was holding
it vertically between fingers and thumbs, just lining it up with the
frame when suddenly - KAPOW!! without any warning or provocation the
whole pane exploded instantaneously in mid air, and landed in a heap of
tiny pieces all over my feet. It must have looked like a Tom and Jerry
cartoon; I was left there holding out my empty hands with a stunned look
on my face.

Clearly I need to have a discussion with the glass supplier tomorrow
morning. It seems to me that the pane was flawed in some way - was the
toughening process done wrong in some way - plausible? Is this sort of
thing common? I'm just envisaging the reaction of the supplier tomorrow
- if he refuses to play ball and tells me I bashed it or dropped it I
would like some knowledge at my fingertips!

I'm also concerned at another level - had this spontaneous breakage
occurred an hour later the pane would have been in situ and the property
empty for the night, and therefore totally open to burglary. And if the
glass is so fragile, WTF is the point of paying for it to be toughened?

Would appreciate any comments (before tomorrow!).
David