The South Acton shuttle was withdrawn on 28 February 1959, followed by the peak hour District line through service to Hounslow on 9 October 1964. In the 1970s the Hounslow branch became the Heathrow branch when it was extended to serve Heathrow Airport, first on 19 July 1975 to serve Hatton Cross, and then on 16 December 1977 when Heathrow Central opened. The whole District line service could not run through Aldgate East as this station was also served by Hammersmith & City trains, so some trains terminated at a bay platform at Mansion House, leaving the line east to Tower Hill overcrowded. Tower Hill station was also cramped, so the station was rebuilt with three platforms on a new site. This opened in 1967 and a year later trains reversed at the new station.