Negligence is not presumed simply because an accident has occurred. In order to establish a prima facie case of negligence, plaintiff must offer evidence that defendant owed him a duty of care, that defendant breached that duty, and that defendant’s breach was the actual and proximate cause of plaintiffs injury. *324 Burr v. Everhart, 246 N.C. 327, 98 S.E. 2d 327 (1957). If plaintiff fails to show any one of these elements, it is proper for the court to enter a directed verdict in favor of defendant.
It is the exceptional negligence action, however, where a directed verdict is entered. On a motion for directed verdict, the court must view the evidence in the light most favorable to the plaintiff. Where plaintiff receives the benefit of every reasonable inference, the issues of reasonable care and breach of that care are usually for the jury. Williams v. Power & Light Co., 296 N.C. 400, 250 S.E. 2d 255 (1979); Robinson v. McMahan, 11 N.C. App. 275, 181 S.E. 2d 147, cert. denied, 279 N.C. 395, 183 S.E. 2d 243 (1971).
In the present action, the court concluded there was insufficient evidence to require submission of the issue of defendant’s negligence to the jury. We disagree.
Defendant, as general contractor, subcontracted with plaintiff’s employer for the installation of the building’s roof. Plaintiff was, therefore, an invitee to whom defendant owed a duty of ordinary care. Benton v. Construction Co., 34 N.C. App. 421, 238 S.E. 2d 655 (1977), cert. denied, 294 N.C. 182, 241 S.E. 2d 517 (1978). When defendant furnished a ramp which was the only access to the building’s roof, it could reasonably foresee that plaintiff would use the ramp. Defendant owed plaintiff the duty to use proper care in the ramp’s construction. See Casey v. Byrd, 259 N.C. 721, 131 S.E. 2d 375 (1963).
Plaintiff argues that defendant breached that duty as a matter of law by violating certain federal OSHA regulations. These regulations require guardrails for open runways four feet or more above ground and toeboards wherever tools and materials are likely to be used on the runway. We disagree that defendant’s noncompliance constituted negligence per se.
The Occupational Safety and Health Act of 1970 (OSHA) was enacted to assure safe working conditions for employees. 29 U.S.C. §§ 651-678. It authorizes the Secretary of Labor to set mandatory safety standards. 29 U.S.C. § 651. In G.S. 95431(a), the General Assembly of North Carolina has adopted the Secretary’s occupational safety and health standards as the rules and regulations of the North Carolina Commissioner of Labor. Plaintiff con*325tends that the adopted regulations establish a standard of care and are enforceable by criminal sanctions. When noncompliance with an administrative safety regulation is criminal, the rule in North Carolina is that the violation is negligence per se in a civil trial. Swaney v. Steel Co., 259 N.C. 531, 131 S.E. 2d 601 (1963).
According to G.S. 95-139, however, a willful violation of an OSHA rule constitutes a misdemeanor only if said violation causes the death of an employee. For all other violations, the sanction is a possible civil penalty accessed by the Commissioner. G.S. 95-138. We conclude that the adopted OSHA regulations are not penal in nature, and, therefore, a violation does not constitute negligence per se. Accord Otto v. Specialties, Inc., 386 F. Supp. 1240 (N.D. Miss. 1974).
OSHA regulations are, however, some evidence of the custom in the construction industry. See, e.g., National Marine Service, Inc. v. Gulf Oil Co., 433 F. Supp. 913 (E.D. La. 1977), aff’d 608 F. 2d 522 (5th Cir. 1979); Knight v. Burns, Kirkley & Williams Const. Co., Inc., 331 So. 2d 651 (Ala. 1976). See generally Annot., 79 A.L.R. 3d 962 (1977) (violation of OSHA regulation as affecting tort liability). Custom is admissible to establish the standard of care required of reasonable men in the same circumstances. 1 Stansbury, N.C. Evidence § 95 (Brandis rev. 1973). Therefore, by presenting evidence that defendant had violated certain OSHA regulations, plaintiff presented some evidence on the issue of defendant’s negligence. See Flying Service v. Thomas, 27 N.C. App. 107, 218 S.E. 2d 203 (1975).
Plaintiff’s evidence also showed that, defendant’s ramp gave under the weight of people crossing it. The accident occurred when one side of the ramp tilted, suggesting that it was not anchored in place. The ramp was located over an open trench which was ten to twelve feet deep.
We hold that such evidence was sufficient to permit a finding that defendant failed to exercise ordinary care in the construction of the ramp and that the results of its failure were foreseeable. It was error for the court to find no negligence as a matter of law.
Defendant argues that the court nevertheless properly entered a directed verdict because plaintiff’s evidence established contributory negligence as a matter of law. We disagree.
*326Contributory negligence is a jury question unless the evidence is so clear that no other conclusion is possible. R.R. v. Trucking Co., 238 N.C. 422, 78 S.E. 2d 159 (1953); Ridge v. Grimes, 53 N.C. App. 619, 281 S.E. 2d 448 (1981). In the present action, reasonable men could differ as to whether plaintiff exercised ordinary care in working from a ramp which lacked guardrails. Conflicting conclusions could also arise concerning plaintiffs balancing of weight on the ramp. There was no evidence that plaintiff’s fall was caused by loose gravel which he should have observed.
Because the evidence will support a finding that defendant’s negligence was the proximate cause of plaintiffs injuries, the court erred in directing a verdict in defendant’s favor. The order is reversed.
Judges MARTIN (Robert M.) and ARNOLD concur.