Alberto Camargo was killed when his tractor rolled over as he was driving over a large mound of manure in a corral belonging to Tjaarda Dairy. Camargo was an employee of Golden Cal Trucking, and Golden Cal Trucking was an independent contractor that Tjaarda Dairy had hired to scrape the manure out of its corrals and to haul it away in exchange for the right to purchase the manure at a discount. Plaintiffs, Camargo’s wife and five children, sued defendants Tjaarda Dairy and Perry Tjaarda on the theory, among others, that they were negligent in hiring Golden Cal Trucking because they failed to determine whether Camargo was qualified to operate the tractor safely. Is Tjaarda Dairy liable for Camargo’s death? [Camargo v. Tjaarda Dairy, 25 Cal. 4th 1235 (2001).]