Talk to your insurance co.

Ransley's right on that point. Insurance companies all have weasel clauses that
let them off the hook for unoccupied house damage. Get professional help to
freeze proof the place (document it!), send letters asking neighbors to check
the place daily (more documentation!), visit daily if you can and keep a record
of visits (still more documentation!), ask your police or fire department for
any help they can offer and note who you talked to and document it. That will
give an even chance that should a bad event occur you can collect on the
insurance. There will be a rate increase, so be brave when you pay the bill.
Good luck.

Joe