Have you ever prevented an accident or saved someones life?

Question is self-explainatory.
It cound be physically or suicide prevention or just sudden super high risk-reduction.

My awnser:
Once a few years ago while nightdriving I was going up a steep hill, about 100m in length, there was a speeding car coming up behind me fast (maybe 160km/h or 200miles/h), they decided to make a pass, I saw headlights coming from behind the hill, he didn't, partly because of mine.

In a split second I turned off my headlights and started breaking to make space for him. It was very narrow but he just barely reacted and turned into my lane as both cars crested the hill.
If they had collided, one or more would have rolled downhill, been flung out into the forest or into me, I'd probably be stationary though as I was breaking uphill.
Still, some people shouldn't be driving.
Have you ever prevented an accident or saved someones life?
Post Opinion