The Concorde was retired in 2003 due to a "perfect storm" of safety concerns and financial losses. The 2000 crash of Air France Flight 4590, which killed 113 people, shattered the aircraft's reputation for safety and led to its temporary grounding. Although the planes were retrofitted with reinforced fuel tanks, they returned to service just before the September 11 attacks, which caused a global downturn in the aviation industry and a sharp decline in the wealthy "business class" market that Concorde relied on. By 2003, the aging fleet required increasingly expensive maintenance for which spare parts were no longer in production. Airbus, the manufacturer, eventually decided to stop providing technical support for the airframe, making it impossible for British Airways and Air France to continue flying. The combination of high maintenance, low passenger demand, and a lack of profitability in a 2003 economy that was shifting toward efficiency over speed sealed the Concorde's fate forever.