A “natural accumulation” of ice and snow is not considered a “property defect” and failure to remove it does not constitute a violation of the landowner’s duty of reasonable care to those lawfully on his premises. Sullivan v. Brookline, 416 Mass. 825, 827 (1994) Liability may attach, however, to “unnatural accumulations” of snow and ice where “some act or failure to act has changed the condition of naturally accumulated snow and ice, and elements alone or in connection with the land become a hazard to lawful visitors.” Aylward v. McCluskey, 412 Mass. 77, 80 n.3 (1992). However, snow shoveling alone is generally not sufficient to convert a natural accumulation into an unnatural accumulation. If an individual is “injured by slipping and falling on snow and ice that remains after shoveling or plowing, that alone is not grounds for a finding of negligence.” Sullivan, 416 Mass. at 827-28. See, e.g., Goulart v. Canton Hous. Auth., 57 Mass.App. 440, 443 (2003) (incomplete snow removal that removes snow but leaves a layer of ice is not grounds for a finding of negligence when someone slips and falls). Likewise, piling snow uphill of a walkway onto which it then melts and refreezes is not grounds for a finding of negligence in Massachusetts. See Cooper v. Braver, Healey & Co., 320 Mass. 138, 139-40 (1946).