In Lo v. Honda Motor Co., 73 Wn. App. 448, 869 P.2d 1114 (1994), when the pregnant plaintiff, Elizabeth Lo (Lo), started the engine of her Honda car, the vehicle suddenly accelerated uncontrollably. Lo was unable to stop the vehicle with the brakes alone, so she thrust the gear-shift lever backward and forward in an effort to kill the engine. Before the engine died, she was thrashed about violently by the jerking of the vehicle. Soon after the incident, she experienced vaginal bleeding and premature contractions. One month later, she gave birth to her son prematurely. The child was diagnosed as a spastic quadriplegic with cerebral palsy. Lo related her son's injuries to his premature birth--which she believed was caused by the physical trauma she received in her car. Within three years of the car incident, Lo commenced a product liability lawsuit against Honda, alleging that her car was defective and caused the accident that led to her child's premature birth and cerebral palsy. An expert physician later opined that medical negligence had caused or contributed to the child's condition. More than four years after her son's birth, Lo amended the complaint against Honda to add the hospital and treating doctors as additional defendants. In Lo, the plaintiff believed that the negligence of one entity, Honda Motor Company, caused the injury. The court declined to hold as a matter of law that her belief also commenced the discovery period as to the other potential defendants, the hospital, and the doctors who delivered the child. Rather, the court stated that there may not be a duty as a matter of law to inquire specifically about the possibility of medical malpractice "where there is another facially logical explanation" for the injury. Lo, 73 Wn. App. at 456. In Lo, the court determined that the appropriate inquiries an injured plaintiff must make depend on the circumstances of the case--due diligence was a question for the trier of fact. Lo, 73 Wn. App. at 464.