Plaintiff wandered drunk into a parking garage owned by defendant and engaged in “horseplay,” ending up sitting on a 43 inch tall perimeter wall on an upper story of the garage, from which she fell to the ground, severely injuring herself. Plaintiff claimed that the defendant had hired a security service to, among other things, find and stop horseplay, as it was banned by the Code of Conduct for the shopping area in which the garage was located. Under Delgado v. Trax Bar & Grill (2005) 36 Cal.4th 224, this was a claim of negligent undertaking, not premises liability. And no duty was owed to plaintiff on the negligent undertaking theory because defendant’s hiring of security guards didn’t increase the risk of injury to plaintiff and she didn’t rely on the guards to her detriment.