See also the document on the Northern Suburbs.
C20 During the 1920s the road and rail links to Mankhurd and Trombay were completed. The Sion-Trombay road was improved and the railway line between Kurla and Chembur was extended to Mankhurd.
The industrial diversification that began during World War II led to a movement of the population beyond the northern suburbs of the 1930s. In 1947, the Committee on Industrial Development came to the conclusion that "Trombay [is] ... most suitable ... [because of its] proximity to the deep water jetty and [being] far removed from residential populations". This thinking continued after the independence, when a petroleum refinery was set up in Trombay during the first Five Year Plan.
This rapid industrial expansion during and after the War had a huge and unforeseen impact on the demand for housing and the attendant infrastructure. The residential sprawl soon followed the railway line to Mankhurd.