Until 1950, runways of Mines Field (or Los Angeles Airport, the future Los Angeles International Airport LAX) did not extend west of Sepulveda Boulevard. About that year, the airport runways were extended to 6,000 feet and Sepulveda Boulevard had to be rerouted around the west end of the runways. In 1953, a tunnel was completed beneath the runways that allowed Sepulveda Boulevard to again run straight and pass beneath airport runways. The tunnel was the first of its kind.