Continental, Delta, TWA, and USAir ended service to LGB, and American Airlines left in early 2006. Alaska Airlines later ended mainline service, and ended codeshare service in 2015. Delta Connection and American Eagle regional jet flights continue at LGB. In February 2016 Southwest Airlines announced plans to begin service to the airport with an initial four available slots. On July 9, 2020, JetBlue announced that they would end service to the airport in October 2020, instead expanding their operations at nearby Los Angeles International Airport. Military use To attract the United States Navy, the City of Long Beach built a hangar and an administrative building and then offered to lease it to the Navy for $1 a year for the establishment of a Naval Reserve air base. On May 10, 1928, the U.S. Navy commissioned the field as a Naval Reserve air base (NRAB Long Beach). Two years later the city built a hangar and administrative building for the United States Army Air Corps as well. Significant developments to the little city airport began only after the city built hangars and administrative facilities for the Army and Navy in 1928–30. As a Naval Reserve Air Base the mission was to instruct, train and drill Naval Reserve personnel. A ground school was offered three nights a week at the base and two nights a week at the University of California in Los Angeles until 1930, when ground school was continuously offered at the base. On April 9, 1939, training in night flight began, and shortly thereafter its facilities began to be used by fleet aircraft as well. With increased activity by airlines and the private airplane industry, particularly with Douglas Aircraft showing an interest in the Long Beach Municipal Airport, the facility needed more space. With Douglas Aircraft as a resident, the attitude of Long Beach's authorities became openly hostile to naval aviation, with its city manager saying that "the sooner the Navy gets out of the Long Beach airport, the better we will like it." The Navy began a survey for another site, unknown to city officials at the time. Admiral Ernest J. King, then the Chief of the Bureau of Aeronautics, and Admirals William D. Leahy, Joseph K. Taussig, and Allen E. Smith pointedly requested that the city of Long Beach repair the runways and reminded the city that the Pacific Fleet, then lying offshore in Long Beach and