Isn't this just covered by ordinary tort law? There is a duty of care, there is a lapse of said duty. The issue seems to be that people are putting valuable items into it and then signing a contract that says that the limit of liability is limited to much less than the value. If that isn't negotiable with the bank then the bank is just not willing to accept the risk. Then either you can find an insurer who is willing to accept the risk or you can find a different bank who is willing to accept the risk or you can build a safe yourself since all the risk is on you anyways.
There doesn't need to be special laws for everything.
There doesn't need to be special laws for everything.