million to settle claims related to the recall. Ford and Firestone worked to settle cases out of court to avoid punitive damages and were paying between $4 million and $8 million to settle cases involving fatalities and between $12 million to $16 million to settle cases of paralysis. Lawyers for the plaintiffs argued that both Ford and Firestone knew of the dangers but did nothing, and that Ford knew that the Explorer was highly prone to rollovers. Firestone argued that Ford's recommended inflation pressure of 26 psi was too low and should have been 30 psi, and that the Explorer was an especially dangerous vehicle prone to rollovers. Congressional investigation Congress began hearings in September 2000 to find out why it took so long for NHTSA to discover these tire defects and why Ford and Firestone were aware of tire failures as early as 1996 but never reported the information to NHTSA. The investigation led Congress to pass the Transportation Recall Enhancement, Accountability and Documentation Act or TREAD Act on October 11, 2000 which was signed into law on November 1. Ford/Firestone corporate relations Relations between Ford and Bridgestone/Firestone deteriorated after NHTSA began investigating the tire failures in May 2000. Ford first accused Firestone of withholding data that Ford needed to determine which tires might be unsafe. Firestone then accused Ford of withholding safety data concerning the design of the Explorer. After Firestone agreed to the initial recall of 14.4 million tires on August 9, 2000, NHTSA continued to push Firestone to recall all ATX, ATX II, and Wilderness AT tires regardless of where they were manufactured. Ford executives were concerned that NHTSA might decide that the Wilderness AT tires would not meet future safety standards and decided to recall these tires on their own. Before Ford could publicly announce this decision John T. Lampe (Chairman & CEO of Bridgestone/Firestone) announced on May 21, 2001 in a public letter to Jacques Nasser (Ford Motor Company chief executive) that Bridgestone/Firestone would no longer enter into new contracts with Ford Motor Company, effectively ending a 100-year supply relationship. The letter included accusations that the Ford Explorer was unsafe and called on NHTSA to investigate design flaws in the SUV. On May 22, 2001, angry that Firestone would not expand the recall, Jacques Nasser at Ford announced a voluntary recall of all Wilderness AT tires that were not subject to the original recall.