when i was at school we had been on a trip and were coming back through Blackheath (SE London) and some little kids (about 8 or 9 years old) fired a stone at the window with a catapult... shattered it completely!
Quite a good job it was good quality glass because it stayed in place... otherwise there would have been glass everywhere and probably quite a few injured children
It was quite amusing seeing the bus driver chase after them though

never seen a sixty year old run so fast