In a hope to aid procrastination and offer some interesting reading this blog is about the May 6th 2010 Flash Crash.
The crash occurred in the USA equity product market, with the Dow dropping 900 points. No one is entirely certain as to the cause of the crash, the consensus blame seems to fall on HFT (High frequency traders) triggering a mass sell-off following a large call to sell in the derivatives market.
This video is worth a watch, you can hear the despair in his voice when he takes a breath around 2 and a half minutes in:
An executive summary can be read here regarding the events: http://www.sec.gov/news/studies/2010/marketevents-report.pdf