This is all pretty hypothetical, and I should say that I am not commenting on any known set of facts or how it would apply in any particular jurisdiction, so this is not to be relied upon for legal advice, but with that disclaimer: The word "accident" is unusual at law. If you are saying that it was an "inevitable accident", then that is a defence. The most typical example of an "inevitable accident" is a car-accident due to black ice. Your second suggested scenario seems to involve over-crowding. That could mean there is a third party claim to be made against whomever (presumably) jostled the person who broke the object, by that person. There would also be a likely claim against whomever controls the store, for "contributory negligence" in allowing the place to be overcrowded, leading to a hazard, leading to the incident that caused the loss. Simple stuff, really.