It's probably something every athlete is afraid of: failing in one event, scoring 0 points and no matter how good you feel - the competition is over for you. Probably the most common failure is having "no measure" during pole vault, because of a very risky starting height. Same for high jump of course, but that happens less frequently. You might also fail, because of three invalid attempts in a row in long jump, discus or javelin throw and shot put, probably not so often during the last two. And, last but not least, the good old false start in all the running disciplines, especially now that the rules about that have changed.

And it does not only happen to young and unexperienced athletes - some examples:

1988, Olympic Games Seoul: Jürgen Hingsen, in his last big championship, loses all chances of becoming Olympic champion because of 4 false starts in the 100m

1992, US Olympic Trials in New Orleans: Dan O'Brien, top favorite for the Olympic Games, got no height during the pole vault, thereby didn't qualify for the Olympics

1997, World Championships Athens: Chris Huffins, before the javelin throw in 3rd place, manages to foul all three attempts; all chances for a medal are lost…

These are just some examples, for tragic events that can happen to any athlete anytime, no matter how good the shape might be…