Shattered glass

After the long day on Saturday, I was sitting in front of my tv playing Pro Evo 5. At about 2am, there was suddenly a loud crashing noise coming from my kitchen/toilet. I first thought it was my frying pan dropped on the floor from the loose hook, but the kitchen was ok. Then my toilet. OH MY GOD!!! One of the glass doors of my shower was shattered into pieces. How on Earth could this happen? It just burst from inside by itself.







If you have an idea how this could happen, please drop a comment. Many thanks.