Whomever owns the property next door is legally liable for damage to other properties caused by negligence in maintaining it. If the foreclosure has in fact gone through, that owner will be either (1) the bank or other lender which foreclosed on the mortgage (or the government, if it was a tax foreclosure), or (2) whomever bought it in foreclosure auction, if the sale's been held. The best case for you would be (1), since those are deep-pocketed entities. If foreclosure is just "in the works" but the property has not yet been foreclosed upon, then the homeowner--the one who's being foreclosed on--would still be the owner, which would be bad for you--that's the person least likely to actually have the money to pay for damages. You should speak with an attorney about initiating a lawsuit against the responsible parties.