The courts distinguish between two types of such accumulation, natural and unnatural. Natural accumulations of snow and ice are wholly the result of nature. Snow, as it falls and accumulates, freezes, melts and refreezes on fields, roads, sidewalks and exterior stairways is considered in the same category as fallen leaves, rain and sunshine. In the absence of an obligation in law, contract or practice, persons walk upon such accumulation at their own risk. The landlord has no liability.
Unnatural accumulations are modifications of natural accumulations.
Water which drips upon a walkway from an overhead rain gutter and subsequently freezes creates potential liability on the part of the gutter owner, the landlord. Snow in a parking lot which is plowed into a pile blocking a sewer and preventing proper drainage of melt water, which then freezes, also creates such potential liability. Further and more importantly from the perspective of a tenant, if a tenant takes it upon himself or herself to shovel a walkway, they must do it properly. If they do it in a manner that endangers walkers, either by doing the job inadequately or by creating a clear path adjacent to snow which subsequently melts and refreezes on that walkway, potential liability is again created, this time on the part of the tenant. When such an obligation exists, a landlord who fails to meet that obligation in a timely manner is potentially liable.