From what we were told back then.
Mentioned being the first class through the completed course.
We were also told, how the obstacle course came to be. For SF training, they wanted the best/toughest. In short. That course came to be, because the powers to be, spent a few years touring and examining other Military obstacle courses around the globe. They chewed it all over and came up with Nasty Nick.
Which by the way wasn't what it was called when I went through. I don't believe it had an official name back then. It DID have a slew of unofficial names that we gave it while running it and after.

Even if I could remember all of them, I wouldn't be able to type them here.
Another couple recollections. The meat wagons were busy. Quite a few guys in them and next to them on stretchers, getting saline injections and whatever. When those guys came to, whether there or in the ambulance on the way to the hospital. Thing is......... when they regained conciousness, and asked....... well, they were told that they were terminated. Don't know if that term is used today in that situation. Was then.
One more memory.
Those of us that got through that day. This was just the first time. And could remember our name and some of us even our number.

The victory and elation was short lived. After 20 or so minutes of rest, water and salt tabs, The instructors decided that there wasn't enough attrition. Nooooope Just 15 or so. Isn't life grand? We got to run the course AGAIN!!!!!!!!!
Seems they were fairly satisfied after the second run. They about doubled the casualities from the first.