P.R. Laws tit. 31, § 3050
Should the conditions be established for the purpose of suspending the efficiency of the obligation to give, the following rules shall be observed in case the thing should improve, or be lost or impaired while the condition is pending:
(1) If the thing was lost without fault of the debtor, the obligation shall be extinguished.
(2) If the thing was lost by the fault of the debtor, he is obliged to make good the losses and damages.
It is understood the thing is lost when it perishes, becomes unsaleable, or disappears in such a manner that its existence is unknown, or it is not possible to recover it.
(3) If the thing deteriorates without fault of the debtor, the deterioration shall be borne by the creditor.
(4) If the thing should deteriorate by the fault of the debtor, the creditor may choose between the rescission of the obligation and its fulfilment, with indemnity for damages in both cases.
(5) If the thing should improve by its nature or by time, the improvements accrue to the benefit of the creditor.
(6) If it should improve at the expense of the debtor, the latter shall have no more rights than those granted a usufructuary.
History —Civil Code, 1930, § 1075.