From 1947 to 1974, George Corson worked as a machinist in several locomotive repair and maintenance facilities. He subsequently died of malignant mesothelioma, caused by exposure to asbestos during his employment. Corson’s widow and executrix brought state-law tort claims against Respondents Railroad Friction Products Corporation and Viad Corporation, entities responsible for the manufacture and distribution of asbestos-containing locomotive parts. The district court dismissed Corson’s case—asserting that the Locomotive Inspection Act (“LIA”) preempted the state-law claims—and the United States Court of Appeals for the Third Circuit affirmed this determination. Corson’s representatives argue that their state claims are not preempted because the LIA only regulates those locomotives that are in actual use. The Respondents, however, contend that the state-law claims are precluded because the LIA was intended to regulate the entire field of design and construction of locomotives. The Supreme Court’s decision will determine the preemptive scope of the LIA, and will establish the appropriate boundaries between states’ traditional regulatory power over railroad safety and Congress’s power to establish national uniformity in railroad-safety standards.