What is a landowner's duty to exercise reasonable care to avoid exposing others to an unreasonable risk of injury?

It is established that a landowner owes a duty to exercise reasonable care to maintain his or her property in such a manner as to avoid exposing others to an unreasonable risk of injury. (Barnes v. Black, supra, 71 Cal.App.4th at p. 1478.) A landowner's duty of care to avoid exposing others to a risk of injury is not limited to injuries that occur on premises owned or controlled by the landowner; "the duty of care encompasses a duty to avoid exposing persons to risks of injury that occur off site if the landowner's property is maintained in such a manner as to expose persons to an unreasonable risk of injury offsite. [Citations.]" (Ibid.)