I was at T1 that day. It was a very serious shunt and, amazingly, Wallek walked away without any serious injuries. Then to lose him in March 2001, while leaving Sebring International Raceway following practice for the 12 Hours of Sebring. Wollek had a tradition of cycling between the circuit and his accommodation. While he had been riding close to the edge of the pavement, he was struck from behind by a van driven by an elderly driver.
Here's a video of the shunt and the laps leading up to it.
https://www.youtube.com/watch?v=_WD3KW4ajQk