In Coughlin v. Harland L. Weaver, Inc. (1951) 103 Cal. App. 2d 602, an individual viewing a house for sale fell down a flight of stairs which was concealed behind a closed door. She sued both the owner and the real estate agent showing the house. The trial court granted nonsuit in favor of the agent, but the Court of Appeal reversed, finding that the plaintiff was a business visitor and that the agent was a possessor within the meaning of section 343 of the Restatement of Torts, which states that a possessor of land "is subject to liability for bodily harm caused to business visitors by a condition thereon if he (a) knows, or by the exercise of reasonable care could discover, the condition which, if known to him, he should realize as involving an unreasonable risk to them, and (b) has no reason to believe that they will discover the condition or realize the risk involved therein, and (c) invites or permits them to enter or remain upon the land without exercising reasonable care to make the condition reasonably safe or to give a warning adequate to enable them to avoid the harm." (Id. at pp. 605-606.)