Five Hundred Billion

[martini]

As to risk and risk mitigation, insurance, like banking works on the principal that not everyone will withdraw simultaneously.  Insurance companies 'package up' their risks and trade them with other companies to diversify their risk, just like banks do with mortgages.

In large-scale disasters, it's usually the reinsurers who get hit, and I'd expect the same thing here, unless the insurance company hadn't adequately protected themselves by getting appropriate reinsurance, or unless they insure something so specialized that other insurers won't touch it.