To prove a design defect, the plaintiff has to show that: (1) there was a safer alternative; (2) the safer alternative would have prevented or significantly reduced the risk of injury, without substantially impairing the product's utility; (3) the safer alternative was both technologically and economically feasible when the product left the control of the manufacturer. TEX. CIV. PRAC. & REM. CODE ANN. 82.005(a)-(b) (Vernon 1997). Texas has adopted the Restatement (Second) of Torts section 402A to define strict tort liability as: (1) One who sells any product in a defective condition unreasonably dangerous to the user or consumer or to his property is subject to liability for physical harm thereby caused to the ultimate user or consumer, or to his property, if: (a) the seller is engaged in the business of selling such product, and (b) it is expected to and does reach the user or consumer without substantial change in the condition in which it is sold. Firestone Steel Prods. Co. v. Barajas, 927 S.W.2d 608, 613 (Tex. 1996) (quoting from Restatement (Second) of Torts 402A (1965)). A product may be unreasonably dangerous due to a defect in its manufacture or design (design defect), or a failure to provide adequate warnings or instructions (marketing defect). Caterpillar, Inc. v. Shears, 911 S.W.2d 379, 382 (Tex. 1995).