Richard Rock worked on an oil rig owned by Huffco Gas & Oil Company (Huffco) (defendant). Rock claimed that his foot had fallen through a rusted step on the rig, resulting in a sprained ankle. There were no witnesses to this incident. After Rock recovered from the ankle injury, he went to work on an oil rig owned by Dual Drilling Company (Dual) (defendant), and subsequently claimed that he had slipped on grease and reinjured his ankle. No one saw this incident either. As a result of the ankle injuries, Rock saw Dr. Delmar Walker and Dr. Fritz Rau (doctors). Rock gave the doctors a history of the two incidents. Rock died the following year. Rock’s family members (plaintiffs) brought a negligence suit against Huffco and Dual. The plaintiffs sought to introduce into evidence Rock’s written and oral statements to the doctors regarding the incidents. In depositions, the doctors stated that for purposes of medical treatment, they needed to know only that Rock had hurt his ankle, not necessarily the details of how he hurt his ankle. The district court found that Rock’s statements to the doctors were inadmissible hearsay. The district court granted the defendants summary judgment, finding that there was no admissible evidence that Rock had injured his ankle on the rigs. The plaintiffs appealed.