China was plunged into great turmoil throughout the 1911 Revolution. Hong Kong became a haven where Chinese refugees, rich or poor, made home, and the influx caused dire housing shortage. In response, a group of Chinese gentries and merchants led by Ho Kai and Au Tak proposed to reclaim Kowloon Bay for the construction of an upmarket Chinese residential district, the fill material to be extracted from Ngau Tau Kok. Though approved, the project was broken off by the economic downturn and the series of strikes in the 1920s. Things came to a standstill: the residential district was less than half-completed, the large plot of reclaimed land was abandoned, and the reclamation scheme was left unfinished.

The idle site became active again only after 1924, when westerners started to rent the reclaimed area, then called Kai Tak Bund, for aviation use. Later the British Air Force also leased the place and used it as a temporary airfield. At length, the government decided to acquire the land, upon which the unfinished reclamation was finally completed and the site turned into the Royal Air Force Airport. In the 1930s, therefore, the reclaimed land was divided into two portions: Kai Tak Bund residential district and Kai Tak Airport. Kwun Tong, on the other hand, was developed into a landfill.

To make Kai Tak an air base, the Japanese government started to expand the site, firstly by bulldozing the walls of Kowloon Walled City and a large part of Sacred Hill (Sung Wong Toi), then by filling the coast, with the clay and debris collected from the demolition, to consolidate the airport foundation and reclaim bits of the land.