I concur in the conclusion that the instruction concerning the measure of damages was prejudicially erroneous, but I dissent from the order directing that a new trial be limited to the issue of damages only.
*664The complaint alleged that the “plaintiff and the defendant entered into an oral and written contract, whereby defendant agreed to furnish to plaintiff the necessary power for the operation of plaintiff’s fish hatchery, and further agreed that in the event it was necessary to suspend temporarily the delivery of electric energy, said defendant would give a reasonable notice to plaintiff. . . . That on or about the 4th of July, 1948, defendant without warning to plaintiff did cause an interruption in the supply of electrical power to plaintiff’s fish hatchery, and that as a direct result thereof and before plaintiff could take the necessary steps for the protection of the fish contained in said fish hatchery, some 78,000 rainbow trout died from lack of fresh water.”
These allegations state no cause of action either in contract or in tort. They include no statement that the power company did not give notice, as it assertedly promised to do, nor do they charge it with any failure to exercise reasonable diligence.
The case was tried upon the theory that the power company was liable under the terms of the oral contract relied upon by Langley. As stated by his counsel in resisting a motion for a judgment on the pleadings, “The issue is simple. There was an agreement to give this man notice that the power was disconnected; the power was disconnected, and he wasn’t given notice. I don’t know how else you could say it.” Similar statements were made by him in his opening statement to the jury, in his closing argument, and in resisting a motion for a directed verdict. In connection with this last proceeding, counsel for the power company asked: “In order that we may put in our defense, will the Court indicate the theory upon which we may be held liable?” The court’s reply was: “The plaintiff’s testimony shows . . . the plaintiff’s claim of an oral agreement.”
The issue of the power company’s liability was submitted to the jury under alternative theories of recovery. By one instruction, the jurors were told: “In addition to the terms of the written contract, there is evidence of an oral agreement between the parties providing for the giving of notice to the Plaintiff by the Defendant in the event of any interruption of power. If you find that such an agreement existed, the duty and obligation of the Defendant to give such notice cannot be excused by any circumstances, and if you find that the defendant made such an agreement and then failed to fulfill it and, *665as a result thereof, the Plaintiff sustained damage, your verdict must be in favor of Plaintiff....”
A rule of the Public Utilities Commission which, by statute was a part of the written contract for service to Langley, stated the duties of the company in the event of an interruption in the delivery of power. The contract, as enlarged by the rule, provided for the very contingency which is the basis of the cause of action, and parol evidence was not admissible to prove a collateral oral agreement relating to the same subject. (Kunz v. Anglo & London Laris Nat. Bank, 214 Cal. 341, 346-347 [5 P.2d 417] ; Pacific States Securities Co. v. Steiner, 192 Cal. 376 [220 P. 304] ; Heffner v. Gross, 179 Cal. 738, 742 [178 P. 860] ; United Iron Works v. Outer H. etc. Co., 168 Cal. 81, 84-85 [141 P. 917] ; Germain Fruit Co. v. J. K. Armsby Co., 153 Cal. 585, 594 [96 P. 319].) Accordingly, evidence as to a contemporaneous oral agreement was erroneously admitted, and an instruction upon that theory should not have been given.
The jurors were also instructed that by the written contract of the parties, the power company was liable for any loss or damage occasioned by the interruption of power if such loss or damage was caused by the failure to exercise reasonable diligence. They were told that, in appraising the conduct of the company, they should determine whether it knew of the hazardous nature of Langley’s business and whether it reasonably should have foreseen that an interruption in the supply of current would result in loss to him.
In deciding in favor of Langley upon the issue of liability, the majority say that there is no necessity to decide the question as to the admissibility of the parol evidence “if under the written contract defendant assumed the duty to exercise reasonable diligence to notify plaintiff of any interruption in the supply of power.” It has been held that “[i]n cases where it clearly appears that the jury did not rely upon the erroneous instructions, the judgment may be affirmed on the ground that the error is not prejudicial.” (Oettinger v. Stewart, 24 Cal.2d 133, 140 [148 P.2d 19, 156 A.L.R. 1221].) But here the record does not show that situation. Instead, it presents a case tried by counsel for both parties solely as one for damages arising from the asserted breach of an oral contract to give notice.
The basis for the conclusion that the erroneous instruction as to the oral contract was not prejudicial is quite uncertain. Reference is made to Heple v. Kluge, 114 Cal.App.2d 473 *666[250 P.2d 694], in which it is stated that an erroneous instruction is not prejudicial “ ‘when the facts as to which the charge is made are admitted or uncontradicted, or where no other conclusion could be reasonably made from the evidence.’ ” (P. 483.) Apparently, then, the power company is held liable upon the ground that, as a matter of law, the evidence shows a duty to exercise reasonable diligence to prevent damage by giving Langley reasonable notice of any interruption in the supply of power.
In challenging the propriety of the instruction which stated that it “was liable for any loss or damage occasioned by the interruption of power if such loss or damage was caused by the failure to exercise reasonable diligence,” the power company points to the written contract which provides that “The Company will not be liable for interruption or shortage or insufficiency of supply, or any loss or damage of any kind or character occasioned thereby, if same is caused by inevitable accident ... or any other cause except that arising from its failure to exercise reasonable diligence.”
That this provision of itself does not create the duty stated in the instruction, apparently is conceded in the opinion in which it is stated: “These provisions deal with the duty to supply power, and they make clear that defendant is not an insurer or guarantor of service. In no way, however, do they abrogate defendant’s general duty to exercise reasonable care in operating its system to avoid unreasonable risks of harm to the persons and property of its customers. (See Pub. Util. Code, § 451.)” It appears, therefore, that the basis of the determination of liability is not a duty specifically created by the contract, but instead a general statutory one requiring a public utility to exercise reasonable care toward its customers, and the written contract is of importance only to prove such a relationship.
No case is cited which holds that a power company may be held liable for a failure to notify customers of an accidental interruption of the supply of electricity, as opposed to a situation where the company suspends the supply of power to effect repairs or for similar purpose. Brame v. Light, Heat, & Water Co., 95 Miss. 26 [48 So. 728], and Stroup v. Alabama Power Co., 216 Ala. 290 [113 So. 18, 52 A.L.R. 1075], are cases in the latter category. Nor is such a charge made in the complaint, which alleges only that the “plaintiff and the defendant entered into an oral and written contract, whereby defendant . . . agreed that in the event it was neces*667sary to suspend temporarily the delivery of electric energy, said defendant would give a reasonable notice to plaintiff. . . ."
The complaint states no cause of action whatever, but the case was tried upon the theory that the power company had made an oral contract to give notice to Langley which it failed to fulfill. Evidence in support of such theory was received erroneously by the trial court and the jury instructed to return a verdict for Langley if it found that such a contract was made and breached. The jurors were also told that, by the written contract, the power company was liable to Langley for damages to his property because of a failure to exercise reasonable diligence “to notify him that the power was off.” That instruction states a theory of recovery inconsistent with the one based upon an oral contract under which a failure to give notice was said to be inexcusable “by any circumstances.”
It is now held that evidence offered to prove an oral contract might properly have been considered by the jury as the basis of liability upon the inconsistent theory of liability under the written contract. For that reason, the liability of the power company is said to now be established as a matter of law, under a theory not pleaded in the complaint nor relied upon by the parties at the trial and upon which the jury was not instructed.
Under certain circumstances, an appellate court may hold, as a matter of law, that specific conduct does or does not amount to reasonable care toward a plaintiff. (Cf. Pirkle v. Oakdale Union Grammar Sch. Dist., 40 Cal.2d 207 [253 P.2d 1] ; Gray v. Brinkerhoff, ante, p. 180 [258 P.2d 834].) But in those cases, the issue of the reasonableness of the conduct involved was presented by the pleadings and considered by the parties with full opportunity to present evidence upon it. The present record shows an entirely different situation.
I would reverse the judgment without qualification.
Appellant’s petition for a rehearing was denied December 3, 1953.
Edmonds, J., and Schauer, J., were of the opinion that the petition should be granted. Dooling, J. pro tem., did not participate therein.