As we've noted elsewhere (see, e.g., "Why Many Slip and Fall On Snow and Ice Cases Fail in New York's Courts," and "Looking for a Prime Example of Constructive Notice of a Defect in NY? Here it is"), a cornerstone of negligence cases, particularly as they pertain to slip or trip and fall cases in New York, is that the defendant who is charged with responsibility for maintaining his property in safe condition, may only be held liable for a claimant who was injured due to a defective condition on his property under one of three (3) scenarios: (1) if he created the defective condition; (2) if he actually knew about the defective condition, but didn't correct it in a reasonable amount of time; or, (3) if he should have known about the defective condition, yet failed to undertake reasonable measures to correct the condition.
This is the doctrine of actual or constructive notice.
Importantly, and as a corollary to that rule, in order to prove that the defendant had notice of the condition, it is incumbent on the plaintiff to prove not only that the defendant knew or should have known that the area was "dangerous" in general; the plaintiff will have to prove that the defendant knew or should have known about that particular condition that caused the injury.
As New York State's highest court put it: "A "general awareness" that a dangerous condition may be present, however, is legally insufficient to create constructive or actual notice of a plaintiff's specific injury-causing condition." Piacquadio v. Recine Realty Corp., 84 NY2d 967, 969 (1994).
As a practical matter, that also means that the plaintiff will be required to show, via competent evidence (rather than mere speculation) how long that specific defect was there before the plaintiff's accident.
And, in most cases, that is no simple matter.