Earlier quoted context omitted.
I'll throw my hat in the ring. Recently had a car totaled when getting it shipped cross country. Apparently because it was an "Act of god" (a hailstorm, with what looks like fist-sized-rock-hail in that every piece of glass and most trim on the car had holes in it, although I'd argue the insurance was for the idiot driver who didn't pull over or cover his load.) the insurance company refused to do squat. The car was…
Insurance companies cannot credibly cover acts of god, aka correlated risks, because they happen to too many people all at once. It's not a simple matter of "fixing" insurance for those matters. NPR's Planet Money had a good discussion: http://www.npr.org/sections/money/2014/10/03/353030214/bedbu...
Of course they can cover. It's a matter of how much you pay for your insurance, and to a large degree how much they company saves up. In the case of a hailstorm it's not because they cannot pay, it's because they don't have proper savings to cover it. A hailstorm with fist size hails is not going to cover the entirety of California, so it's very manageable.
An example, when a fireworks factory in Denmark exploded the total claim of material damage was 750 million DKK (113 million USD). The vast majority was covered by insurance companies, even though that would fall under correlated risks. One of the way insurance companies handle this is to have a joint fund with other insurance companies (I think this is government mandated), where they can withdraw in cases like this.