I hope you can track down the cause, but as Pbakk mentioned above, that can be a challenge to do. That’s the tough thing since you certainly don’t want to be repairing it and then having it happen again.
In the end, you’re most likely the one on the hook for it. It is not something that would be covered under warranty. IF you can determine the cause, and a specific person or entity is responsible for that cause, you would have to go after them to cover it (assuming they don’t take care of it voluntarily). Not a great spot to be in, in that regard.
Not at all what anyone wants to hear in a horrible situation like this, but in all likelihood, that is the reality.
All of this said, I would think it would fall under your boat insurance coverage, should you wish to file a claim. Have you talked to your insurance agent to get a read on the situation from them about coverage and your situation? Depending on extend of damage, I would think that is really your only other option outside of yourself.