Pan Am celebrated its 50th Anniversary of Trans-Atlantic service in 1989. Boeing 314s originally flew from New York's Marine Air Terminal to the Azores and on to Southampton, UK. The celebrations were marred by the terrorist downing of Flight 103 over Lockerbie, in December 1988. Many consider this the final straw in the declining fortunes of "The World's Unluckiest Airline", whose bookings had just improved prior. One year later, Pan Am would sell its Heathrow routes to United.