Tall Shower Doors How Is It Possible For A Glass Shower Door To Shatter On It's Own?

How is it possible for a glass shower door to shatter on it's own? - tall shower doors

I have a separate shower. The partition is a half wall between the tub and shower in the air, and sits on the half wall is a wall of glass. I do not know how, but spontaneously broken, the glass wall by itself. It started with a bang, and broken 20 minutes all the windows.