At the risk of sounding callous or insensitive, I have to be the devil's advocate for sporting events of any sort, not just endurance events;
Any sport carries with it inherent risk or danger to oneself or others. To me, that is what separates them from everyday life. These casualties, while unfortunate, are probably not easily forseeable, even by physicians. I sympathize with any who are dealing with mortality or morbidity associated with a sports casualty, but I hope that, if anything, occasions such as these do not discourage people from continuing or beginning athletic endeavours. The rewards of participation are so all-encompassing that I don't need to describe them.
I'm curious to know if anybody here has lost a loved one to a sports-related tragedy.