Schoolchildren participated in a historical reenactment at the Chalmette National Battlefield. D's refinery is adjacent to the battlefield released an amount of petroleum coke dust that Madison (Ps) migrated over the battlefield. Ps filed suit, seeking a variety of damages, including personal injury, fear, anguish, discomfort, inconvenience, pain and suffering, emotional distress, psychiatric and psychological damages, evacuation, economic damages, and property damages. The district court allowed the parties to conduct discovery on the issue of class certification. D deposed each of the five named class representatives. Ps then moved for class certification under Rule 23(b)(3), asserting that this lawsuit is a type of action where 'questions of law or fact common to class members predominate over any questions affecting only individual members, and that a class action is superior to other available methods for fairly and efficiently adjudicating the controversy.' Two years later, the district court held a hearing on the motion to certify the class. At the conclusion of that hearing, and without any evidence being introduced, the district court orally granted Ps' motion. D appealed.