Counsel for defendant have accurately selected the. question of duty as their prime target. A finding of negligence turns upon two elements, first, the existence of a duty to use care, and second, a breach of such duty by the creation, of an unreasonable risk of harm. (McEvoy v. American Pool Corp., 32 Cal.2d 295, 298 [195 P.2d 783]; Routh v. Quinn, 20 Cal.2d 488, 491-492 [127 P.2d 1, 149 A.L.R. 215]; Rest., Torts, § 281 a, b.) A third element necessary to establish actionable negligence, is proximate cause. (Cases cited 35 Cal.Jur.2d 549, fn. *2; Rest., Torts, §§ 281, 430.) Inquiry into proximate causation, however, presupposes an affirmative finding of negligence, based upon the dual occurrence of a duty and its breach. (Richards v. Stanley, 43 Cal.2d 60, 69 [271 P.2d 23].) A duty of care, owed by the alleged wrongdoer to the injured plaintiff or to a class of which he is a member, is indispensable to negligence liability. (Richards v. Stanley, supra, 43 Cal.2d at p. 63; Hatch v. Ford Motor Co.,* 163 Cal.App.2d 393, 397 [329 P.2d 605].)
One factor in the delineation of duty is the foreseeability of harm. (Richards v. Stanley, supra, 43 Cal.2d at p. 66; 38 Am.Jur. 669, Negligence, § 24; Prosser on Torts (2d ed.) 168; see Prosser, Selected Topics on the Law of Torts, Palsgraf Revisited, pp. 191-242.) Foreseeability is equally pertinent in the exploration of proximate cause, especially where an intervening act plays a contributory role in the accident. (Eads v. Marks, 39 Cal.2d 807, 812 [249 P.2d 257]; McEvoy v. American Pool Corp., supra, 32 Cal.2d at pp. 298, 299; Bilyeu v. Standard Freight Lines, 182 Cal.App.2d 536, 542 [6 Cal.Rptr. 65].) Divergent results are possible and judicial disagreements arise by approaching negligence determinations through the gateway of duty, on the one hand, or proximate causation on the other. (See Richards v. Stanley, supra, 43 Cal.2d 60; Mosley v. Arden Farms Co., 26 Cal.2d 213, 220-223 [157 P.2d 372, 158 A.L.R. 872], concurring opinion; Prosser, Proximate Cause in California, 38 Cal.L.Rev. 369, 412-415; Green, Duties, Risks, Causation Doctrines, 41 Tex.L.Rev. 41.)
We make these observations in view of the variant approaches of California decisions on negligence liability of school districts, some of which have been cited to us as precedents. Several cases illustrate the method of initial inquiry into the existence of duty. Thus Kerwin v. County of San Mateo, 176 Cal.App.2d 304, 307 [1 Cal.Rptr. 437], and Girard v. Monrovia City School Dist., 121 Cal.App.2d