On 19 February 1942 Japanese bombs fell on mainland Australia for the first time. The port and city of Darwin suffered two devastating attacks by over 188 Japanese aircraft that day.

Over the next twenty months northern Australia was to endure almost a hundred air raids, from Exmouth in the west to Townsville in the east. At the same time, Japanese submarines attacked merchant vessels off the coast of eastern Australia.

Reactions to these attacks varied across Australia. For those close to the areas under attack, the damage was obvious and the response immediate.

The population in southern Australia was shielded from the detail of the attacks by distance and wartime censorship. Nevertheless, strict air raid precautions were implemented and the civilian population prepared to face the national emergency.

On the night of 31 May – 1 June 1942 three Japanese midget submarines attacked Sydney Harbour. They were launched from a group of five larger submarines waiting off the Heads. All three midget submarines were lost, with two of them destroyed before they could fire their torpedoes. The third fired at but missed the USS Chicago, sinking HMAS Kuttabul, a coverted ferry, and killing 21 sleeping sailors aboard. Reactions by Sydney residents varied; a few made plans to flee the city, but many came to watch the recovery of the submarines.

A week after the midget submarine attack on Sydney Harbour, two of the larger submarines returned to bombard Sydney and Newcastle with their deck guns. One shelled Newcastle for twenty minutes until driven off by fire from coastal artillery defences. Another submarine fired ten rounds into eastern Sydney.

http://www.awm.gov.au/exhibitions/underattack/bombed/