Northwest Airlines reduced its fares and offered special business perks to attract customers at the same time as fuel prices spiked. In 2005 they filed for bankruptcy and later merged with Delta.
In 2001, Trans World Airlines (TWA) flew its final flight. The company was officially sold to American Airlines after decades of saddling debt. In 1991, the company was forced to sell its lucrative London routes — accelerating their demise.
The airline had severe financial difficulties in the early 2000s, filing for chapter 11 bankruptcy twice in two years. In 2005, America West Airlines carried out a reverse merger and acquired it's assets.