This is a situation where you need to weigh the costs of losing relationships against a potential law suit. Without knowing more about the property or the situation, it's difficult to tell whether you may have a suit and what kind it would be (one for which you would hire an attorney or one dealt with in small claims court). You also need to balance the cost of a lawsuit against the likelihood that this person would actually pay you if you won a judgment. I'd suggest you contact a personal injury attorney to discuss the facts. If this isn't the right kind of attorney, they'll let you know who to contact next. A phone consultation shouldn't cost anything. You can use Avvo's Find a Lawyer search tool to look for local attorneys.
The information provided in this answer does not create an attorney-client relationship and is not considered to be legal advice.
I agree with the previous answer and if the bailee standards apply it would appear the real property owner is a gratuitous bailee and has a duty of care of personal property left in their care. Plaintiffs will be able to sue for damages based on the duty of care. Often this will be normal tort damages. Plaintiff may elect also to sue for conversion, either in the replevin or trover, although these are generally considered older, common law damages.
Please be sure to indicate the best answer. If this answer was helpful, please mark as helpful below. Only. If and until you and I sign an Agreement for Legal Services, I am not your attorney. These answers are provided for informational and/or novelty purposes