I would get a licensed contractor out to give a professional and documented opinion on the soundness of the structure, with photos identifying any issue.
I would then give the resident notice of the problem with a copy of the contractor’s report, and 30 days to put a plan in place to repair or remove the building.
If they don’t respond, I would then have the contractor repair or remove the building and then have the park bill the cost back to the resident.
I personally wouldn’t involve any additional 3rd parties besides a licensed contractor.
Just my 2 cents, and I obviously haven’t seen the park or the structure in question.