An engineering flaw is a fence that allows that entire 3400 pound car to go through and come to rest in the stands. Most of that car ended up thrown right back out on the track where it belonged, which is the point of that fence. It's unfortunate that people were injured, but the catchfence did what it was designed to do, and that's hold back as much as possible. Can't think of another fence that would hold back an entire vehicle that gets flung at it at speeds nearing 200 mph. Perhaps plate tracks should scale back the seating by several rows to keep people from getting so close to the fences.