Yep. But the runners also should have realized that the conditions were less than ideal. I would have dropped out, or not run in the heat of the day. That was idiotic.
I just read the story on ESPN.com. The man who died was only 35. This suggests that either he wasn’t in shape for a long run in the heat, or that he had undiagnosed heart disease already. Sometimes middle-aged guys just drop, after even moderate exercise.