read it last summer...the description of the Gordon Smiley accident is gruesome...you can youtube the accident in which they go frame by frame and you can see his helmetless head halfway out of the cockpit as the car is climbing the fence...
Back then the chassis was fabricated aluminum similar to aircraft of that era. Sort of an interim step between the old steel tube frame and the current carbon fiber. The speeds advanced much quicker than the structural integrity of the chassis.