Why was the fall of Singapore a significant event for Australians.

Australia was looking even harder in America's direction when, just four days after the Singapore surrender, Japanese war planes bombed Darwin. ... The fall of Singapore was a military defeat that ushered in years of horror for Australian prisoners of war. It was also a capitulation with profound strategic consequences.

Explanation:

Yes you are right, voting is the best important civic responsibility. Civic responsibility or civic engagement refers to the sense of personal responsibility citizens feel to uphold their duties or obligations  as part of the community.