Investigators are still trying to figure out why an 18-year-old runner collapsed on a busy Carlsbad street and died.
Bystanders found Ian Patrick Phillips, 18, just before 6 p.m. Tuesday on Tamarack Avenue near Jefferson Street.
Investigators say Phillips collapsed while running and was not hit by a car. He was taken to Tri-City Hospital, where he later died.
The cause of death is not yet clear.
Phillips was student at Carlsbad High School, according to the North County Times.