Before bringing this up, it's important to note that dying during a triathlon is very, very rare.
This year, however, there was some buzz about it after someone died in the New York City Triathlon and The New York Times wrote a story about it.
Most recently, Beginner Triathlete (BT) published a really good article on it, prompted, I assume, from the questions asked late this summer after the news story.
Here is the BT story.
Here is The New York Times story.