While filming the movie "Giant," film icon James Dean was interviewed in a Warner Brothers featurette involving members of the film's cast while they were on the set. The host plied the young actor with questions about his interest in auto racing. At the end of their brief exchange, he asked, "Do you have any special advice for the young people who drive?" to which Dean responded, "Take it easy driving, the life you might save might be mine."
About a month later, on 30 September 1955, Dean was killed in a car accident when his new Porsche Spyder crashed head on into another car. Most historians agree Dean had been speeding at the time of the accident (with many saying he had been traveling at up to 90 to 100 mph) and that this excess of speed was the cause of the fatal crash.
(from snopes.com)