So they briefed the government. I bet the government in Oz got briefed on ebola and meteor impact sink holes and all sorts of very low risk things.
Very LOW risk. Like, it's happened twice in two hundred years and almost nothing of consequence was the result.
And I said: they happen all the time -- what's your point. It seems to be "it might happen therefore we should all freak out about it". It's all very alarming.
One or two cities having the population of your entire country

yeah pretty weak.