The Firestone and Ford tire controversy of the 1990s saw hundreds of people die in automobile crashes caused by the failure of Firestone tires installed on light trucks made by Ford Motor Company. Unusually high failure rates of P235/75R15 ATX, ATX II, and Wilderness AT tires installed on the first-generation Ford Explorer and similar vehicles caused crashes that killed 238 people and injured around 500 others in the United States alone; more died in other countries. The revelations halved the market value of Bridgestone, which fired or accepted the resignation of several executives and closed the Decatur, Illinois, factory where the tires were manufactured. Ford also fired or accepted the resignation of executives. Each company publicly blamed the other for the defects, a disagreement that ended the companies' nearly 100-year relationship. Congressional inquiry into the scandal led to the enactment of the Transportation Recall Enhancement, Accountability and Documentation (TREAD) Act in October 2000. Problem detection As early as 1996, personal injury lawyers were aware of accidents, injuries, and deaths caused when the tread separated from Firestone tires at high speeds. Lawyers and traffic safety researchers decided not to contact the National Highway Traffic Safety Administration (NHTSA) because they lacked confidence in the agency and feared that an investigation might conclude that there were no defects, thereby compromising existing personal injury lawsuits. All but 13 of the 271 known deaths from these tires took place after 1996. In 1996, the Arizona state government told Firestone that the treads on its tires were separating in high temperatures. Firestone sent several engineers to inspect the tires and concluded that normal passenger tires were being used in heavy conditions, on dirt roads, off-road, and under heavy loads. Firestone replaced those tires with heavier-duty tires. As early as 1997, internal Firestone documents showed a rise in injury claims for the ATX, ATX II, and Wilderness AT tires. In July 1998, Samuel Boyden, a researcher for State Farm Insurance, received a call from a claims handler asking for information about tread separation in Firestone tires. Boyden subsequently found 21 crashes caused by tread separation and forwarded the information to NHTSA. In 1999, he found an additional 30 cases which he also forwarded to NHTSA. In 1998, Ford began replacing Firestone tires in Venezuela, where 46 deaths had occurred, according to documents uncovered by Sean Kane, a researcher at Strategic Safety Consulting. Firestone was aware of tire