Alleging that petitioner Norfolk & Western Railway Company (Norfolk) had negligently exposed them to asbestos and thereby caused them to contract the occupational disease asbestosis, respondents, six former Norfolk employees (asbestosis claimants), brought this suit in a West Virginia state court under the Federal Employers Liability Act (FELA). Section 1 of the FELA provides: "Every common carrier by railroad while engaging in [interstate commerce], shall be liable in damages to any person suffering injury while he is employed by such carrier in such commerce ... for such injury ... resulting in whole or in part from the [carriers] negligence." As an element of their damages, the asbestosis claimants sought recovery for mental anguish based on their fear of developing cancer. The trial court instructed the jury that a plaintiff who demonstrated a reasonable fear of cancer related to proven physical injury from asbestos was entitled to compensation for that fear as a part of the damages awardable for pain and suffering. T