Authorities believe a medical emergency is the reason behind the death of a 50-year old Santa Cruz man, who died while cycling in Felton today. Officers say the man was riding a bike with a group of cyclists north on Highway 9 at about 9:40 this morning, when he crashed into a concrete curb and a picket fence. The man was taken to the hospital where he died. His identity has not been released. Highway 9 near San Lorenzo Way closed for about half an hour while emergency crews responded.