what if my house was to burn down while i was in contract to sell it

I hope you have insurance to repair or replace the house in the event there is a fire loss.  Depending on where you are in the process of contracting with the buyer, the buyer may have a contract interest in such insurance proceeds.  If you have no insurance and there is a loss, and if the buyer has suffered a loss because of the absence of insurance, you may have a lawsuit by the buyer to contend with.  (The purchaser of real estate will usually have significant expenses in preparing for the closing -- such as the purchase of an appraisal, a survey, title services, etc - and even the payment to the prospective lender of servicing fees.  The process can be quite expensive.)