(2-part post):
Let's start with an analogy. Suppose you slip on a spilt liquid in your local Tesco and break your arm. If you could show that the Tesco staff had known about the spill for several minutes and had failed to clear it up (or at least put a 'wet floor' sign up), you'd be in position to successfully sue Tesco for compensation. In practice, the matter would probably be settled out of court and their insurers would pay you an appropriate sum.
However, if the spill had only happened seconds earlier, and there was nothing that Tesco staff could have done to prevent your accident, you'd have no chance of getting any money out of them or their insurers
The difference is that of negligence. To successfully sue someone, you have to show the person (or company) you're suing was responsible for the the injury (or damage) because they were negligent.
To take a real example (which is a little closer to your own situation), the actor Gordon Kay suffered a horrific head injury when a piece of an advertising hoarding broke off during a gale and smashed through his car windscreen, penetrating his skull. He successfully sued the company who owned the advertising hoarding, forcing their insurers to pay out, because his legal team proved that the hoarding had been allowed to get into a poor state of repair. (i.e. the owners were negligent in failing to recognise the potential danger of the situation).