Lee Sanchez, Jr. bled to death from injuries sustained when his Chevy pickup truck, manufactured by General Motors Corporation (GM) (defendant), rolled backward and pinned him between the open driver’s side door and a gate. Sanchez’s family, his wife, and his estate (plaintiffs) brought a products-liability claim against GM, alleging a defect in the truck’s transmission. Although there were no witnesses to the accident, the plaintiffs theorized that Sanchez had exited the truck to close the gate, leaving the truck door open and the engine running, and had mistakenly shifted into an intermediate position between gears. As he walked toward the gate, the gear shift slipped into reverse, and the truck rolled backward into Sanchez. The truck's owner's manual included a discussion of safety measures to take upon exiting the truck to ensure that the truck would not move when parked. These safety measures included setting the parking brake, placing the truck completely in park, turning off the engine, removing the key from the ignition, and pulling down on the gear shift to ensure that the parking gear was fully engaged. Although Sanchez's father testified at trial that Sanchez probably read the owner's manual, the plaintiffs' experts all agreed that Sanchez had not performed any of these recommended safety measures before exiting the truck. The experts further agreed that if Sanchez had performed any one of the safety measures, the accident would not have occurred. The jury found that the transmission was defective and that GM had failed to give an adequate warning, but that Sanchez was 50 percent responsible for the accident. The trial court disregarded the finding that Sanchez was partially responsible and awarded the plaintiffs $8.5 million in damages. The court of appeals affirmed. GM appealed to the Texas Supreme Court. On appeal GM argued, among other things, that the trial court improperly refused to apply comparative responsibility to reduce the plaintiffs' recovery. The plaintiffs contended that comparative responsibility did not apply in their action based on strict products liability because Sanchez's negligence was nothing more than the failure to discover or guard against a product defect.