Seller agreed to deliver 1,000 air conditioners to Buyer DES Port Moresby. The air conditioners were transported by ship to Port Moresby, where they were off-loaded to the customs shed for inspection. The ship then sent a cable to Buyer stating that the air conditioners were in the customs shed and that the ship was proceeding on its way. Before Buyer could arrive to pay the customs duties and collect the air conditioners, the customs shed burned down, destroying all the air conditioners. Buyer sues Seller for failing to make delivery. Is Seller liable?