The Supreme Court described the "death knell" exception to the one final judgment rule for class actions, saying, "The right to appeal in California is generally governed by the 'one final judgment' rule, under which most interlocutory orders are not appealable. (See Code Civ. Proc., 904.1.) In Daar v. Yellow Cab Co. (1967) 67 Cal.2d 695, however, concerned that orders dismissing all class action claims might in some instances escape review, we adopted a 'death knell' doctrine that allowed a party to appeal such orders immediately." (In re Baycol Cases I & II (2011) 51 Cal.4th 751 at p. 754.) The Supreme Court reviewed the origins of the doctrine, explaining: "In Daar, the plaintiff filed a putative class action. The trial court sustained a demurrer, concluding the plaintiff could neither maintain a class action nor satisfy the jurisdictional minimum amount in controversy for superior court actions, and transferred the action to the municipal court. On appeal, we considered as a threshold issue whether such an order, determining the plaintiff could not maintain his claims as a class action but could seek individual relief, was appealable, and we concluded it was. What mattered was not the form of the order or judgment but its impact. (Daar, at pp. 698-699.) Because the order effectively rang the death knell for the class claims, we treated it as in essence a final judgment on those claims, which was appealable immediately. " (Baycol, supra, 51 Cal.4th at p. 757.) The court added: "Equally important in Daar was the circumstance that the order appealed from was essentially a dismissal of everyone 'other than plaintiff.' (Daar, supra, 67 Cal.2d at p. 699, italics added.) We emphasized that permitting an appeal was necessary because 'if the propriety of a disposition terminating class claims could not now be reviewed, it can never be reviewed' (ibid.), and we were understandably reluctant to recognize a category of orders effectively immunized by circumstance from appellate review. This risk of immunity from review arose precisely, and only, because the individual claims lived while the class claims died. As the United States Supreme Court has explained, 'the "death knell" doctrine assumes that without the incentive of a possible group recovery the individual plaintiff may find it economically imprudent to pursue his lawsuit to a final judgment and then seek appellate review of an adverse class determination.' " (Baycol, supra, 51 Cal.4th at p. 758.)