The Nurburgring circuit is very famous not only for its complexity but also for the number of recorded accidents. Every year dozens of accidents occur and in a few bad cases, some pilots have lost their life.
The height difference and limited vision turn some curves in real traps and at high speeds, it can prove fatal. An example is this video which clearly shows that the brakes are virtually ineffective in cases when the obstacles occur out of nowhere.
Driving at a speed of 160 km h, as it seems that the speedometer shows, sudden braking does not help and only the fast reaction of the driver saved his life.
Unfortunately, such situations can be encountered on public roads as well, that is why there are private schools where you can take extreme driving lessons training your reflexes.