If you have a good insurance company, regardless of which trailer the fire started at, you would be paid by your own insurance company. After you have your money you move on and get another RV. All the bickering back and forth then goes on by the insurance companies going after reimbursement from each other. If you are not insured then you will be fighting with somebody else's insurance company trying to become whole again. If your unit caused it and you are not insured everybody else's insurance companies will be dealing with you trying to become whole again.