>Could have been a accident that nothing / nobody could have stopped.
Most so called "accidents" are preventable (I would go so far as to say most accidents are nothing of the sort - but easily preventable with a bit of thought).
A car is going to fast, the driver is reading a map or using a mobile phone, the child is not being supervised, the child should not be out at a young age etc etc.
My rather stupid neighbour put a childrens swing in his garden right in front of his greenhouse. If one of the children had fallen off the swing and crashed into the greenhouse people would have said "a terrible accident".
But it was nothing of the sort, the stupid man next door should not have put the swing where he did (as it happens there was no accident and the kids are now grown up).
But few accidents are really accidents but lack of planning or foresight.