The bbc currently have a fascinating 1-hour long documentary on the 1955 Le Mans disaster - an event that shaped and changed motorsport as we know it to what it is today. It's an hour long. I thoroughly recommend it. The final fifteen minutes are particularly poignant.
BBC iPlayer - The Deadliest Crash: the Le Mans 1955 Disaster
For people outside the UK I'm unsure how you can watch this - maybe try some sort of country-masking proxy?
[VIDEO]http://www.youtube.com/watch?v=D74A8JEC_rY]YouTube - 1955 Le Mans Disaster - New Footage[/VIDEO]