This is how fast it happens in Australia:

[Blue_Tires]

Link to tweet

[Wounded Bear]

1. Hot fires, dry vegetation, windy day...

yeah, it happens fast. Works that way in California, too.

[zanana1]

2. What part of Australia had the heavy rain?

I know that Australia is a large country. How much of Australia is dry?

[uriel1972]

8. Practically the entire interior except for rainy seasons

It's complicated but Australia the nation is mostly coastline with some fringes up the Murray-Darling River system.
Australia the continent/island is much, much bigger than Australia the nation

[Baitball Blogger]

3. Holy Smokes!

[lunasun]

4. A guest on my local TV news today just reminded everyone the fires are still going in Australia

May not be top news right now in US, but this is still going on there

[tblue37]

5. Who is taking that video?! These people are incredibly brave. nt

[Recursion]

6. First thing they taught us: you cannot outrun fire

Man that's awful. I hope those responders are OK

[littlemissmartypants]

7. Wow!! Now I see where the phrase 'great balls of fire' comes from.

This is horrible. I hope no one was hurt. I am sad for the helpless animals that were no doubt, in the fire's path.