D is a practicing physician. He hired P as a farm laborer in January 1976. P undertook to repair the roof on a barn. The repairs were to consist of nailing down the edges of the roof that had been loosened by the wind and painting the roof with a coating. P was severely injured when he fell from the roof while applying the coating with a paint roller. P alleges that D was negligent for failing to comply with occupational and health regulations and for his failure to provide a safe place to work. The lower court granted summary judgment to D on the grounds that there was no showing that the injury was caused by the negligence of D. P appealed.