2009 Detroit Half Marathon Deaths

I ran the Detroit Marathon last Sunday morning. It wasn’t until that evening that I heard the sad news that 3 people died running the half.
The autopsies were inconclusive, and the results of some more extensive tests are not due for a few weeks. The fact that there were 3 deaths in one race has attracted attention, and generated a lot of uninformed opinions and even conspiracy theories.
There were especially a lot of dumb comments on this article in the nytimes

Let me paraphrase some of the things I have read:
1. “This proves that marathons are bad for you.” Really? Despite the fact that they were not even running a marathon?
2. “The causes of the deaths are because of unfit people attempting to run races they are not properly trained for.” Actually I think these guys were pretty fit. At least one of them had done multiple marathons.
3. “Because they all died within 16 minutes of each other they must have been poisoned.” Almost all cases of sudden deaths in races seem to happen at (or near) the end of the race, which is the case here. So it just means they happened to be finishing around the same time.

My guess is that these 3 men had some rare, hard to detect heart conditions (which are described here) and the deaths were just random chance. I read that the chance of dying in a marathon is about 1 in 100,000.( For a half marathon I would guess the odds would be even less.) But this does not mean that the deaths will be spread out evenly, and that if 100,000 people ran a marathon exactly 1 would drop dead. No, randomness means events may be spread far apart or come in bunches. For example the last death in the Detroit marathon was in 1994, 15 years ago.