P is a hemophiliac. P received a clotting agent known as Factor VIII. In December 1991, P tested positive for HIV. P sued those providers of Factor VIII which were administered to him between 1979 and 1985. P was uncertain as to which manufacturer provided TAMC, so Ps brought suit against all four manufacturers of the agent. They also sued the United States for negligence and for breach of its duty to warn Ps while they were treated at TAMC. Appellants originally filed suit in Hawaii state court; their cases were subsequently removed to federal district court. The district court granted summary judgment in favor of Ds. The district court held that because Ps could not identify exactly which manufacturers' product had caused their infection, under Hawaii law, they could not bring a negligence suit. Ps appealed and filed motions requesting that the Ninth Circuit certify two questions of law to the Hawaii Supreme Court pursuant to Haw. R. App. P. 13.