A la Japan in the 80's and 90's.
Japan was a bit different: there the boom was financed by actual assets in the form of American real estate. The problem was caused when the same real estate was used as collateral for multiple loans and the real estate market busted.
For example, remember when the Japanese bought Rockefeller Plaza for something like 80 million bucks, and then sold it a few years later (after the real estate market went soft) and they could only get 30 mil?
How many loans do you think were based upon the "nod-and-a-handshake-they have-Rockefeller-center-in-their-portfolio" way? Probably half a dozen, at least. When all that real estate went south, so did the Japanese markets.
Chinese credit, however, probably works in a much different way, since the banking system depends on a wink and a nod from the ostensibly-Communist government (It only exists for the same reason). Many of those loans are probably in the name of a bevy of high government officials and their cronies (and therefore they will never be paid back), not in the name of some rice farmer or rickshaw driver who actually works for a living, nor are they probably backed up by any physical asset (land, mineral rights, buillon, etc).