A young man has died taking part in the Brighton Marathon.
He was attended to by paramedics at the 16 mile mark, near Grand Avenue in Hove.
A spokesman for the Royal Sussex County Hospital confirmed a 23-year-old man collapsed on the course at about 11.45am.
Medical teams were in attendance immediately and made attempts to resuscitate him.
He was taken to the Royal Sussex County Hospital in Brighton by ambulance where doctors continued to give him treatment.
However, he died at about 2.30pm.
A spokesman for the Royal Sussex said his family have been informed.
One runner, who asked not to be named, said medical staff were giving the runner CPR at the side of the course.
She said it was "extremely upsetting".