A seller had manufactured forty thousand pounds of plastic resin pellets especially for a buyer, who agreed to accept them at the rate of one thousand pounds per day upon his issuance of shipping instructions. Despite numerous requests by the seller, the buyer issued no such instructions. On August 18, the seller, after warehousing the goods for forty days, demanded by letter that the buyer issue instructions. The buyer agreed to issue them beginning August 20, but never did. On September 22, a fire destroyed the seller's plant containing the goods, which were not covered by insurance. Who bears the risk of loss? Please explain.