Nothing is 100% SAFE, only a arbitrary level of SAFER. Everything is arbitrary. As pointed out above, the cage level is 10.00. It could just as easily be 9.50 or 10.50. It's just a number somebody selected. So one day you are running 10.0s and your car is legal. The next day you run 9.90s and car is illegal. Is it ANY less safe than it was the day before? Of course not but the line HAS to be somewhere. I do find it odd that safety seems to be the area where most guys will push it to the absolute limit until they just HAVE to do something. They may not be willing to risk that motor on a stock rod and will update to aftermarket to "be safe" and then turn right around and slow the car down so they don't have to upgrade cage, buy a new suit, new helmet, whatever. Never made much sense to me, but it's their azz.

People die in 20mph crashes everyday and some die in 100mph crashes everyday. Many also walk away from such crashes without a scratch. Injury or not just depends on the circumstance. I personally have seen guys walk away from 300mph crashes and saw one die who simply broke an axle on the starting line. Anything can and will happen.