Timeline: Global credit crunch

A year ago, few people had heard of the term credit crunch, but the phrase has now entered dictionaries.

Defined as “a severe shortage of money or credit", the start of the phenomenon has been pinpointed as 9 August 2007 when bad news from French bank BNP Paribas triggered sharp rise in the cost of credit, and made the financial world realise how serious the situation was.

The problems, however, started much earlier.
http://news.bbc.co.uk/2/hi/business/7521250.stm