Article 479 of Civil Code

If the thing sold partially perishes or is damaged before delivery owing to an extraneous cause for which neither contracting party is responsible, the buyer shall have the right to reduce the price in proportion to the diminution in the value of the thing sold. If the destruction or damage is so substantial that, had it existed at the time of sale, he would not have concluded it, he may rescind the sale. All this applies if the destruction or damage occurred before the buyer was formally put in default to take delivery of the thing sold.