The Emerson Electric Co. manufactures and sells a product called the Weed Eater XR-90. The Weed Eater is a multipurpose weed-trimming and brush-cutting device. It consists of a handheld gasoline-powered engine connected to a long drive shaft, at the end of which can be attached various tools for cutting weeds and brush. One such attachment is a 10-inch circular saw blade capable of cutting through growth up to 2 inches in diameter. When this saw blade is attached to the Weed Eater, approximately 270 degrees of blade edge are exposed when in use. The owner’s manual contained the following warning: “Keep children away. All people and pets should be kept at a safe distance from the work area, at least 30 feet, especially when using the blade.” Donald Pearce, a 13-year-old boy, was helping his uncle clear an overgrown yard. The uncle was operating a Weed Eater XR-90 with the circular saw blade attachment. When Pearce stooped to pick up something off the ground about 6 to 10 feet behind and slightly to the left of where his uncle was operating the Weed Eater, the saw blade on the Weed Eater struck something near the ground. The Weed Eater kicked back to the left and cut off Pearce’s right arm to the elbow. Pearce, through his mother, Charlotte Karns, sued Emerson to recover damages under strict liability. Is Emerson liable? Karns v. Emerson Electric Co., 817 F.2d 1452, Web 1987 U.S. App. Lexis 5608 (United States Court of Appeals for the Tenth Circuit)