In Pennsylvania, the authoritative case on slip and falls is Martino v. Great Atlantic & Pacific Tea Company. The plaintiff in Martino slipped on a grape, fell, and sustained a broken leg while shopping at a self-service grocery store. The court held that the store could only be held liable if the plaintiff could prove that “he [it] knows, or by the exercise of reasonable care could discover, the condition which, if known to him [it], he [it] should realize as involving an unreasonable risk to them.” Id. at 233.
The court went on to state: “The mere presence of such refuse, as described, does not in itself show negligence, for this condition may temporarily arise in any store of this character, though the proprietor has exercised due care; and, if it appears that proper efforts are made to keep clean the passageways so they may be safely traversed, he is not to be held responsible if someone accidentally slips and falls.” Id. at 233-34.
Essentially, what Martino boils down to is that slip and fall liability is not strict in nature. Rather, a slip and fall case is a type of negligence action in which the existence of a duty, a breach of that duty, causation, and damages must be proven for a plaintiff to succeed.
The existence of a duty is typically not an issue. A business generally owes a duty to its business invitees, i.e. its patrons. The issue of proof arises at the second step of the negligence action, as it did for Mrs. Martino who failed to meet her burden of proof.
If a potential plaintiff can surpass the breach hurdle, or in the terms of the Martino court, prove that the business knew or had reason to know of the hazard and failed to make the premises reasonably safe, a negligence action may be a good avenue of recourse.
 Martino v. Great Atlantic & Pac. Tea Co., 213 A.2d 608 (Pa. 1965).