public for entry for his business purposes is not an insurer of the safety of such visitors against the acts of third persons .... He is, however, under a duty to exercise reasonable care to give them protection. In many cases a warning is sufficient care if the possessor reasonably believes that it will be enough to enable the visitor to avoid the harm, or protect himself against it. There are, however, many situations in which the possessor cannot reasonably assume that a warning will be sufficient. He is then required to exercise reasonable care to use such means of protection as are available, or to provide such means in advance because of the likelihood that third persons . . . may conduct themselves in a manner which will endanger the safety of the visitor. Id. cmt. 33 (1961) (<HOLDING>); Gurren v. Casperson, 147 Wash. 257, 258-59,
holding that a business owner owes the duty to his guests to exercise reasonable care to protect them from injury at the hands of a fellow guest holding that the law imposes on every person who enters upon an active course of conduct the positive duty to exercise ordinary care to protect others from harm and calls a violation of that duty negligence  that a complete binding contract between the parties is not a prerequisite to a duty to use due care in ones actions     and that architects may be held liable for a breach of the duty of care and breach of contract that results in foreseeable injury economic or otherwise holding that an agent owes a fiduciary duty to his principal holding a business owes a duty to protect invitees from reasonably foreseeable harm by third persons holding that a business owner has a duty to use reasonable care to maintain premises in a reasonably safe condition for patrons