The world is in the midst of the alleged worst economic global crisis (since the 30s with no end in sight, as the powerful USA got caught up with the closure of a venerated brokerage firm and the potential loss of another before being saved by the government. Here's some readings on this crisis:

The bailout of AIG may actually signal more potential financial turbulence up ahead as other larger firms also indulged in the same things it did.
This AsiaTimes article explains why an insurance giant was so affected by the financial crisis.

Whatever the specific financial causes of these events, it's not surprising that a system driven by high lending and borrowing and hence, often unsound loans, would collapse over time. It's smething that's always struck me as unsustainable in the long run, like a "house built on cards" sort of thing.