Thanh Williamson was killed while riding in the second-row aisle seat of a Mazda minivan when it was struck head on by another vehicle. Her seat was equipped with a lap-only seatbelt, which caused fatal internal injuries when the impact of the collision caused her body to jackknife over the belt. After her death, Mrs. Williamson's family brought suit against Mazda, alleging that the van was defective because it lacked a lap/shoulder belt for the aisle seat. When the minivan was manufactured and sold, the relevant federal safety standard allowed but did not require that seat to have a lap/shoulder belt.
Public Citizen Litigation Group served as co-counsel for the Williamsons in the U.S. Supreme Court. The question before the Court was whether the Williamsons' damages claims were barred by implied conflict preemption, on the theory that holding Mazda accountable for failing to install a lap/shoulder belt would pose an obstacle to the federal safety standard in effect at the time. In a unanimous decision, the Court held that the claims were not preempted. The case returned to the trial court, where the Williamsons will have an opportunity to litigate their case on the merits.