Clauses that are silent on pandemics, epidemics, or other viral outbreaks are likely to be insufficient for a force majeure defense due to COVID-19, unless, of course, courts liberalize the force majeure analysis to account for market realities.[11] If a force majeure clause clearly covers COVID-19 as a qualifying event in light of the WHO’s declaration, parties seeking to invoke the provision will not need to establish the event was unforeseeable, but will still need to show: (1) that they took steps to mitigate the damage, and (2) that performance is truly impossible (or meets any other standard the clause requires). 

Also, they haven't moved out yet, so they could do damage to the house.In their defense, they did pre-screen some tenants and find me a replacement.  

Your best defense in all this is to know how to read and interpret your insurance policy.

(Christian)Or the Jewish Defense League?

@Wade Sikkink You're correct that insurance won't protect you from being sued, but generally insurance policies require the carrier to provide you with a defense in case you are sued - so they cover your legal fees.

I would just make sure whatever percentage of the property that you assign to land vs. structure is defensible - how aggressive you want to be is a bit of a judgement call.

I have plenty of information to back my defense the most important being the wording of Massachusetts Landlord/Tenant Law which mentions nowhere that I am responsible for shoveling snow off my roof nor does it say that I am responsible for the personal belongings of my tenants or their guests (the car). 

The neighbor on the other side of my property has told me that the folks with the cats are very defensive when approached about any problems related to their felines, so I have not yet approached them directly.  

Like you, Jay responded defensively.

If you LLC each SFH and you end up with 50+ that's a book keeping nightmare.Your first line of defense for asset protection is good insurance, and simply making sure everything you do is in line with the law.