In Jonathan v. Kvaal (Minn.Ct.App. 1987) 403 N.W.2d 256 (Jonathan), the Minnesota Court of Appeals found a plaintiff's knowledge of the extent of the danger in diving into a shallow pool presented a question of fact for the jury. The 24-year-old plaintiff in Jonathan had previously used the aboveground pool on at least 10 occasions. He was aware of a sign warning against jumping and diving and of depth markers. On one occasion, the plaintiff jumped into the pool from the nearby roof, rousing the pool owner's ire. ( Id. at p. 258.) One evening, the plaintiff drank an unknown quantity of strong beer, jogged alongside the pool, and dove into the shallow end, severely injuring his spine. (Ibid.) The plaintiff considered himself a fair swimmer without any formal instruction and had previously made numerous shallow dives into the shallow end of the pool. (Ibid.) In opposing the defendant's motion for summary judgment, the plaintiff submitted an affidavit by an expert in pool design. The expert stated aboveground pools create risks of injury well known in the pool industry but unknown to the general public. (Ibid.) The trial court granted summary judgment, finding the plaintiff was familiar with the pool based on his frequent use and also describing the plaintiff as an experienced swimmer and diver. The trial court determined the plaintiff's negligence was the sole cause of his injuries and the injuries were not caused by any breach of duty by the pool manufacturer. The appellate court reversed. ( Jonathan, supra, 403 N.W.2d at pp. 258-259.) The court noted that the plaintiff's expert stated the general public was unaware that headfirst diving into aboveground pools posed a risk of serious injury. The plaintiff stated he was unaware he was risking serious injury by entering the pool from ground level. The court concluded: "Here, Jonathan's knowledge as to the extent of the danger in using the pool is a fact issue for the jury. Here, our analysis is not limited to questions of breach of duty only but involve, as well, issues of causation, for liability does not arise unless and until there is a breach of duty that is a direct cause of injury. These are triable issues of fact not to be resolved by summary judgment." ( Jonathan, supra, 403 N.W.2d at pp. 261-262.)