Singapore fell on 15 February 1942 with more than 50,000 men becoming prisoners of war, including the WA raised 2/4 Machine Gun Battalion.

[2][3][4][5] The action was taken to defend against the possibility that a force of Japanese warships and planes would attempt to attack the cities of Fremantle and Perth.

[10][11] Japanese propaganda was produced at the time to spread the idea of invasion or bombing of southern Australian cities.

[13] The events surrounding the bombings and response by authorities in northern Australia were referred to as "Japanese Scare" tactics.

[14][15] The work undertaken in Fremantle and Perth to prepare for an imminent invasion or attack was the most extensive in the history of Western Australia.