What would need to be the conditions/reasons for you to have a IM cancelled/shortened? (Page 2)

yup, this for me as well. Would I be disappointed? Sure, maybe a little bit I suppose. The real question for me is that if the race did get altered, would I still race? IME, an Iron Distance race is a rather big target - If it was shortened to a 70.3 I would probably DNS, and pivot to another IM if possible if that is REALLY what I wanted to do this year. Or at least pull the plug after the bike and have fun watching the race go on. If they only reduced either the bike or run to a single loop and kept the other intact then I would probably still race and call it good. In some way It would actually be cool to race a different format for a change. I don't see shortening the swim having enough impact one way or the other on the race to make a difference. 

It gets hot here too....and when it does, people die of all kinds of heat related issues.  Heat stroke, heart attacks, etc.  And no, I'm not exaggerating how emergency personnel handle these things as I've watched it firsthand for 30 years.  It's a pretty simple formula......if you have a heart attack, for instance, who do you want working on you while you lie on the floor.......the guy who has ran hundreds of calls for heart attacks or the guy seeing his first one.

Sure, it gets hot there, but when it does 2000 people don't take off on a 140 mile journey into it....and surely not on what may be the hottest day on record, ever.  Look, it gets hot there, I get it......but your emergency personnel are much less equipped and experienced dealing with heat issues that the first responders where I am, who are much less equipped than the first responders in La. or somewhere else.  It's the exact reason hundreds of people can die in a heat wave in say, Chicago, while the same heat will kill very few people in La. or Mississippi.  It's not an exaggeration, it's just the way things are.  IF the race goes off in 100 degree+ temps in that area, your emergency systems will be stressed.  It's bigger than the race. (I know how hard that is for people who do triathlon to understand    )

Damn, if they cancel IM CdA you have some REALLY bad luck.   Hope this goes off for you.

LOL, I guess it did need to be in pink.

And the point has been totally missed here....

I ride the fence on this one. 

On the one hand, I completely trust and respect the RD's decision. They know things I don't, and have a team in place making decisions for the good of the participants, volunteers and community. 

On the other hand, I also believe in the athlete's personal responsibility. Now that they've known the forecast for about a week, I would hope athletes have enough foresight to alter their plan accordingly. It might not have been something they specifically trained for, but they're certainly capable, and I would expect them to, research how to race in heat and precautions they need to take in this week leading up to the race - should it go on as planned.

Yes, the event went off and I'm glad they allowed it to do so. According to the Spokesman-Review there were "nearly 300" DNS, 1,710 started and 1,335 finished. 

I'm glad that I kept my commitment and volunteered. Lots of appreciation from the athletes. But my favorite was when an athlete's wife stopped and thanked us. An epic  day and congrats to those who made it through--they're truly an Ironman.

Last year the total registrations at CdA was about 2500 (verified by the 2014 full results that shows 124 pages of athletes including DNF and DNS).  2015 was also sold out and I believe close to 2500 again.

Maybe the reported 300 DNS was of those who picked up their packet?  If so, a 32% DNS rate (1700 out of 2500 started) and a 22% DNF rate is pretty high.