present US Airways terminal), and Terminals C and D would have been connected together. US Airways Shuttle flights would have moved to the Marine Air Terminal, and mainline US Airways flights would have moved to Terminal D (the present Delta terminal). The United States Department of Transportation announced that they would approve the Delta/US Airways transaction under the condition that they sell slots to other airlines. Delta and US Airways dropped the slot swap deal in early July 2010 and both airlines filed a court appeal. In May 2011, both airlines announced that they would resubmit their proposal of the slot swap to the US DOT. It was tentatively approved by the US DOT on July 21, 2011. The slot swap received final approval from the US DOT on October 10, 2011. On December 16, 2011, Delta Air Lines announced plans to open a new domestic hub at LaGuardia Airport. The investment was the largest single expansion by any carrier at LaGuardia in decades, with flights increasing by more than 60 percent, and destinations by more than 75 percent. By summer 2013, Delta increased operations to 264 daily flights between LaGuardia and more than 60 cities, more than any other airline at LaGuardia. In November 2019, Southwest Airlines ended service to Newark primarily due to the Boeing 737 MAX groundings, poor performance, and inadequate facilities, and consolidated its New York–area operations to LaGuardia and Islip. Reconstruction In April 2010, Port Authority director Christopher Ward announced that the agency had hired consultants to explore a full demolition and rebuilding of LaGuardia's Central Terminal. The project would create a unified, modern, and efficient plan for the airport, currently an amalgam of decades of additions and modifications. The project, expected to cost $2.4 billion, will include the demolition of the existing central terminal building and its four concourses, garage, Hangar 1, and frontage roads; building temporary facilities, and designing and building a new central terminal building. The rebuilding would be staged in phases in order to maintain operations throughout the project. Proposals were due on January 31, 2012. Patrick Foye, executive director of the Port Authority, said, "It's got a quaint, nostalgic but unacceptable kind of the 1940s, 1950s feel that's just not acceptable." The Port Authority was seeking a private company to develop and operate the replacement terminal with private funds, similar to how Delta operates the other terminals at the airport.