Flooding will be a trespass or a nuisance and they do not require proof of negligence.
On that point, there’s a lot of even online published legal opinion about strata water leaks, liability and negligence.
Basically to be liable, the event has to be foreseeable. It’s not an absolute liability:
Although that’s for VIC, the same principles apply nationwide.
There are also state Water Acts that can apply but again a test of reasonableness of prediction will be needed.
These are the same kinds of tests needed to establish negligence.
How could a reasonable person foresee a burst pipe or fitting? Maybe they could have. But that’s what you have to establish.