I read this in the tandem forum by DanRH (Hope he doesn't mind me reposting it over here), it's very relevant for many of us in the long distance forum. Instead of paraphrasing I just copied the text of his post.
I rode an extremely tough 200 mile bike ride last week. It was the event's "staff" ride. The event, called the Devil Mountain Double Century" actually occurred yesterday. I was driving my mini-van as a SAG vehicle on the course. All was well in the first part of the day. I fixed numerous flats and chain repairs.
After lunch, I was headed up the back side of Mt. Hamilton. This section is very steep. There is a five mile climb, where the mile numbers are painted on the road, which makes the climb particularly annoying. At the 2 mile mark (at mile 130 on the route), there was a sign on the road indicating water 2 miles. I decided to stop and hand out water at the sign because I'm usually running on empty at this point so I thought I'd provide some additional support. Many, but not all, cyclists stopped to take me up on my offer. Temps were about 80. I've been out there when it was pushing 100 so it was actually very beautiful out. A cyclist came by and asked if I had an energy bar. I told her was all out I and decided to hop in the van and drive to the water stop to get a bar. On the way back, the same gal said a guy was in need of help at the spot I was at earlier. I rushed down there.
There was a friend of mine (who I will not name as he is a forum member, but I will say, he's a hero in my eyes!) who was applying CPR to a fallen cyclist and continued until the sheriff arrived , who took over. A medivac helicopter was called in but since it was in a very remote section of the mountain, they had to be trucked in from a couple of miles. Eventually, the fire department showed up and they called it about an hour in. The fallen cyclist, Tom Milton was 56. I did not know him personally, but had a connection. Tom was a very seasoned rider. As a matter of fact, Tom is the owner and creator of the Selle An-Atomica saddle which Kathryn and I use on all of our bikes. He has done this ride many times and has done many ultra-endurance rides in the past, riding 50 double centuries in the last six years.
He was riding strong. He was actually about three hours ahead of where I was at the same spot last week. The only negative comment he was heard to say was at lunch, 15 miles from where he died. He said he was not looking forward to the upcoming climb because he felt he had nothing in his tank. Tom was riding at about 4-5 miles an hour and apparently died of a massive heart attack. He was riding alone when he fell off the bike.
It was extremely said as we watched this man die. He girlfriend, whom he lived with, of course was in shock at the end of the ride. She had been contacted by the rider organizers and she came to the start/finish point. She usually rides these rides with him, but yesterday did not for some reason. I would think that she is grateful that he died doing something he truly loved. I agree.