Does the creditor have the right to claim from the heirs of the guarantor or the heirs of the debtor if the guarantor and the debtor both died in an accident?

The death of the guarantor does not invalidate the financial guarantee. The ruling of the guarantee remains effective even after the death of both the guarantor and the person for whom the guarantee was given. The rights holder is entitled to demand payment from the heirs of either of them, as the right is established in the liability of both of them together. If the guarantor's heirs pay the right, they have the right to seek recourse against the heirs of the person for whom the guarantee was given to recover what they paid from their deceased's inheritance.