Acctually it is very, very unlickly that the American finance system would have blown. Everytime the US has bailed out banks unter the premis 'to big to fail' later analysis has shown that the impact would have been much smaller.

There is a book about that: "Too Big to Fail: The Hazards of Bank Bailouts"

http://www.amazon.com/Too-Big-Fail-Hazards-Bailouts/dp/08157...

or maybe better for most people a podcast with the auther:

http://www.econtalk.org/archives/2009/10/gary_stern_on_t.htm...

It was acctually the feds intervention (paying banks to hold reserves) not the fall of leeman that froze the holesale lending market.