DALLAS (AP) - Southwest Airlines Co. has begun flights to the southernmost city in the continental United States.
 
Dallas-based Southwest on Sunday began service to Key West International Airport.
 
Key West, Fla., became the 78th city served by Southwest. Key West formerly was served by AirTran Airways, which Southwest purchased last year.
 
Southwest plans to eventually discontinue the AirTran brand but that could take several years.