Hi,
yes, we had that once years ago too. Sounds like a spontaneous fracture caused by nickel-sulfate inclusion. It occurs in about 2% of all doors, is a material defect and therefore actually a case for the warranty. But it is difficult to prove.
We were lucky back then that although the door shattered completely, the fragments stayed in place long enough for me to take a photo. And in the photo, you could see that the cracks originated from somewhere in the middle of the door, so it was not caused by a bump or the like.
I think this will be a case for your glass breakage insurance.
Best regards,
Andreas