Uh I'm wondering why everyone thinks its the tenant's liability for the damage to the furniture?
It seems clearly on the "landlord" side of the responsibility ledger to me. Fortunately it does seem to be something that will fall on an insurer or builder's warranty, but as pointed out, its not the tenant's fault.
Sorry - that's unfortunately not how it works. If you can prove the the Landlords negligence caused the repair, then yes, the tenant would have a case. Apart from that, the tenants would have to rely on their own insurance. What if a tree fell on the house? That's an accident - would the owner be liable because it happens to be their house?