On 2 October 2001 a major cash-flow crisis at Swissair , exacerbated by the global downturn in air travel caused by the September 11 attacks , caused the airline to ground all its flights . Although a government rescue plan permitted some flights to restart a few days later , and the airline 's assets were subsequently sold to become Swiss International Air Lines , the airport lost a large volume of traffic . After Lufthansa took control of Swiss International Air Lines in 2005 , traffic began to grow again
September 11 attacks
September 11 attacks
Zurich Airport