The seller must disclose the damage caused by the tornado to the buyer. The seller should inform the buyer of the damage and either offer to repair the damage before closing or reduce the sale price by the cost of the repairs. The seller could also offer a credit to the buyer for the cost of the repairs if the buyer agrees to assume responsibility for the repairs after closing. In any case, the seller should be transparent about the damage and work with the buyer to find a mutually acceptable solution.