When a person slips on ice or snow, some people think the weather is to blame. New York law may hold otherwise. Following a snowfall or freezing rain, property owners must begin clearing the ice and snow within four hours and must complete the job in a reasonable time. Negligence is the key to premises liability claims involving snow or ice. A property owner may be negligent in snow/ice-related accidents if a premises condition causes an unnatural accumulation of precipitation. For example, if an inefficient roofing system creates an ice dam that leads to a ceiling collapse, the owner may be responsible.