Man... that sucks.
My condolences to the family as well.
It would be nice to know what happened because the car looks like it held up fairly well even without a cage (passenger compartment looks pretty intact)... if there are safety issues with those DOT harnesses (Schroth?) that would be very important to find out since lots of people run them.
Details aside, this is a good reminder that driving is dangerous... not just on the track, but all the time.