Midwest, already in a financially weakened condition following the September 11, 2001 attacks and the aforementioned takeover battle, suffered another severe financial blow as a result of the 2008 fuel price spike. Midwest's fleet of MD-80 airliners had been well suited to its markets and Midwest's high-service business model during the 1990s, but by 2008 it was no longer fuel efficient as compared with newer aircraft designs. Midwest terminated the leases on those aircraft and returned them to their lessors. Shortly thereafter, as the result of a failed lease renegotiation with Boeing, Midwest also lost the leases on 16 of its 25 newer Boeing 717 aircraft, leaving the airline with only 9 of the 38 aircraft with which it had started the year.