That's a tough question. I was a firefighter for quite a while, and every time I went into a burning structure to make an attack, or conduct a search, I was taking a pretty big risk. Was fortunate enough to never get injured or anything doing that, so knock on wood there.
Then there was the time I walked across a railroad bridge, and then - while standing safely off to the side of the rail on the other side - decided to start back across right when I heard a train whistle in the distance. I mean, the train was far enough away that I couldn't even see it and the bridge wasn't that long. And while I don't think I came too close to being killed (I made if back off the bridge with at least 20 or 30 seconds to spare) as I was running across the bridge, looking at the gaps between the ties, and thinking "if my foots slip and goes into one of those gaps, I'm dead" it felt pretty "life or death". I always say, if there is an truth to any sort of "parallel universe" notion, then in at least a few of those realities I probably did die that day.
