Those with blowproof bellhousings

Back in the mid 70s, I was at Wilkesboro Dragway and watched a car run when his flywheel let go. At that time, the spectator seating was concrete, like big steps. It looked like fireworks went off in the car starting with a shower of sparks and then black smoke pouring out as they car drifted to a stop. It was so violent, I thought the driver must be dead. But there were two spiraling smoke trails coming from the top of the car going probably 100 yards upward. One trail went left and one went right. As we all tracked the smoke trail coming towards us, everyone scattered just before half the flywheel hit on the concrete like a sledge hammer. Luckily, no one was hit. The other half landed right by some crew member in the pits. The safety crew drug the driver out of the car and I don't remember him being injured, but he was covered in black dust.