A beautiful evening with a really horrible ending

One evening a friend and I were going for a walk through a forest to a lake just to sit and chat with the gorgeous view of the lake. Going there we passed a jogging trail and we saw a man laying down in his jogging clothes and trainers on his stomach and a woman standing beside him looking around. The man was really exhausted by the look of it. We continued and had a lovely chat by the lake and after about 30 minutes we returned and now the man was still laying on the ground but with a light blue blanket covering him and the ambulance was there. Then we understood that the man had died while running probably a heart attack and we...we had just previously passed by...