cracked window in rear door!!!!

[Jodes]

Got in my car the other morning and noticed a hairline crack right across the window in my rear door.......

I think I have double glazing as crack was only on outer glass but then inside pane cracked after a few miles and another crack then appeared...

Under the circumstances think I can rule out vandalism and given I didn't notice it whilst driving the previous day it seems unlikely it was a pothole!?

Has this happened to anyone else? Any thoughts and will my windscreen protection cover other windows??