PARKER, C.J.

The instant case does not involve an injury to a *317 spectator. We have here the death of a voluntary participant who was killed on defendant’s race track while conducting high-speed tests of Goodyear Tire & Rubber Company tires at a speed of about 150 miles per hour, when the right front tire on the automobile he was operating ruptured and the automobile crashed through a guard rail on the outside edge of the race track, fell approximately 50 feet to the ground, and struck a steel post which came through the left side window of the automobile killing the driver. Do the facts of this case disclose the breach of any duty owed to plaintiff’s intestate by the race track owner?

The general rule is that the owner or operator of an automobile race track is charged with the duty of exercising reasonable care, under the circumstances present, for the safety of patrons and participants in the racing; that is, a care commensurate with any known or reasonably foreseeable danger. Williams v. Strickland, 251 N.C. 767, 112 S.E. 2d 533; Lane v. Drivers Association, 253 N.C. 764, 117 S.E. 2d 737; 37 A.L.R. 2d 391, where many cases are cited; 4 Am. Jur. 2d, Amusements and Exhibitions § 81.

This is said in Annot. 37 A.L.R. 2d 391 at 394, and quoted with approval in the Williams and Lane cases: “If the need is obvious or experience shows that an automobile race of the character and in the place proposed requires, in order to afford reasonable protection to spectators, the erection of fences or similar barriers between the track and the places assigned to them, it becomes a part of the duty in exercising reasonable care for their safety to provide fences or barriers, the adequacy of which is dependent on the circumstances present, principally the custom of the business.” At page 395 of this same annotation will be found a number of cases in respect to the absence or inadequacy of fences, barricades, or other protective devices, where, under the circumstances of individual cases, a recovery has been upheld or denied.

G.S. 1-122 provides that “the complaint must contain ... (2) a plain and concise statement of the facts constituting a cause of action. . . .” (Italics added.) The cardinal requirement of this statute, as emphasized in numerous decisions of this Court, is that the facts constituting a cause of action rather than the conclusions of the pleader must be set forth in the complaint so as to disclose the issuable facts determinative of the plaintiff’s right to relief. Shives v. Sample, 238 N.C. 724, 79 S.E. 2d 193; Griggs v. Griggs, 213 N.C. 624, 197 S.E. 165; Gillis v. Transit Corp., 193 N.C. 346, 137 S.E. 153; Lassiter v. Roper, 114 N.C. 17, 18 S.E. 946; Moore v. Hobbs, 79 N.C. 535.

It is hornbook law that on a demurrer a pleading will be liberally *318 construed with a view to substantial justice between the parties giving the pleader the benefit of every reasonable intendment in his favor; and a demurrer admits, for the purpose of testing the legal sufficiency of the pleading, the truth of factual averments well stated and relevant inferences of fact reasonably deducible therefrom, but legal inferences and conclusions of the pleader will be disregarded. 3 Strong, N. C. Index, Pleadings, § 12.

This is said by Johnson, J., in Shives v. Sample, supra:

“In an action or defense based upon negligence, it is not sufficient to allege the mere happening of an event of an injurious nature and call it negligence on the part of the party sought to be charged. This is necessarily so because negligence is not a fact in itself, but is the legal result of certain facts. Therefore, the facts which constitute the negligence charged and also the facts which establish such negligence as the proximate cause, or as one of the proximate causes, of the injury must be alleged. Daniels v. Montgomery Ward & Co., 217 N.C. 768, 9 S.E. 2d 388; Furtick v. Cotton Mills, 217 N.C. 516, 8 S.E. 2d 597; Moss v. Bowers, 216 N.C. 546, 5 S.E. 2d 826. See also Baker v. R. R., 232 N.C. 523, 61 S.E. 2d 621.”

In Thomason v. R. R., 142 N.C. 318, 55 S.E. 205, Connor, J., said for the Court:

“A complaint which alleges negligence in a general way, without setting forth with some reasonable degree of particularity the things done,. or omitted to be done, by which the Court can see that there has been a breach of duty, is defective and open to demurrer.”

See 'also McIntosh, North Carolina Practice and Procedure, § 359.

In the present case plaintiff predicates her right 'of recovery on (1) the failure of defendant to equip its race track with an adequate and properly constructed guard rail capable of preventing automobiles traveling at speeds in excess of 150 miles per hour from leaving the track when it knew, or in the exercise of reasonable care should have known, that this guard rail was insufficient; and (2) on its failure to warn the drivers on its race track that the guard rail was inadequate. No particular facts are alleged as to- how the guard rail was inadequate or improperly constructed, nor is there any allegation- of fact to show how the guard rail could have been constructed to prevent an automobile which has sustained a blowout at this high rate of speed from plunging through it and off the 'track. There is no factual allegation in the complaint that any other ’ car has broken *319 through the railing at this race track, nor any specific allegations of fact showing how defendant could have been aware of any purported inadequacy of the guard rail. Furthermore, there are no allegations of fact in the complaint showing that it is the general custom and practice among auto raceway proprietors to maintain guard rails capable of absorbing the shock of cars traveling at speeds of 150 miles per hour. The complaint does not allege any specific negligent act of commission or omission on the part of defendant which proximately resulted in her intestate’s death. It is alleged in the complaint that the “defendant knew or in the exercise of due care should have known that the guard rail through which the automobile being driven by the plaintiff’s intestate went was inadequate. . . .” In the absence of supporting factual allegations, this is a conclusion of the pleader to be disregarded. Shives v. Sample, supra.

To paraphrase Justice Connor’s language in Thomason v. R. R., supra, the complaint alleges negligence in a general way without setting forth with some reasonable degree of particularity the things done or omitted to be done by which the Court can see that there has been a breach of duty. Therefore, the complaint is defective and open to demurrer.

The interesting questions of contributory negligence and assumption of risk mentioned in defendant’s brief are affirmative defenses and cannot be raised on a demurrer. 3 Strong, N. C. Index, Negligence § 11; 1 McIntosh, N. C. Practice and Procedure § 1236(13) (2nd Ed. 1956).

HusKins, J., took no part in the consideration or decision of this case.

The judgment below sustaining the demurrer to the complaint is

Affirmed.