[kenoh]

I have literally known 2 people who have died while running a marathon (one 30ish, the other in his mid 40s). It's stupidly abusive on your body, but if you do want to run one, make sure you get your heart fully checked out by a doctor.

[cullenking]

Yup! I watched a 50 year old fit guy drop dead in the first 10 miles of a 100 mile ride. He was gone before he even hit the ground. It's pretty common in hard endurance sports to hear about heart failure, though I think the benefits outweigh the risks in the long term. This is assuming you are training a normal/sane amount, getting plenty of rest, listening to your body etc etc. Work hard play hard doesn't last forever.

[dangerf]

Everything causes death; I would not discourage running a marathon based on your anecdote.