I did not find this but once at a race a dude dropped 10 feet from the finish line.
Another dude and I stepped up and did CPR right away until the medics got there. The dude died saddly. A doc was there and was monitioring his vital signs and said the guy had good color and a solid heart beat (because we were doing CPR correctly)
that was pretty wild.
Wow. That's tragic! Sorry you had to see something like that.