While attending a summer program administered by D on their premises, P rode and ultimately fell from a banister, injuring himself seriously. P seeks to recover upon a theory of negligent supervision. P alleges that at the time of the accident P, then not yet 12 years of age, had been left wholly unsupervised. D moved to dismiss as P assumed the risk of sliding down the banister. P had fallen once before when he attempted the stunt. The court granted the motion. P appealed. The appeals court held that assumption of risk doctrine is not generally applicable in negligence actions to nullify a defendant's duty, but is appropriately interposed only to shield a defendant from exposure to liability arising from risks inherent in athletic and recreational activities. The appeals court reversed and then certified the issue.