Are natural disaster scripted or random? (possible spoiler, if it's scripted)

[goldenpeach]

So, I recently had a major earthquacke in the San Fransisco career map and I was wondering if such events were scripted to happen or if they were purely random.

Can the same event happen during free game?
Does certain maps have a lower chance to have a given natural disaster(assuming it's random)?

[G.R.C.]

I think it's based on the geography terrain, so SF is prone to earth quakes, whereas Calgary isn't.

[3:48 a.m.]

I have a similar question: if earthquake is not scripted, could it repeat after finishing SF-part of career?
Btw as I know, it can't happen in free games, only in career

[Arturczyk]

Scripted.