Teachers and learners at East London's Port Rex Technical High School are mourning the passing of principal, Arthur Pederit.
Fifty-seven-year-old Pederit is believed to have suffered a heart attack while jogging in Sprigg Street in Cambridge.
Deputy principal, Dennis Fairlamb, says they were shocked when they heard the news on Friday morning.
He said Pederit had been the headmaster of Port Rex for the past 14 years.
He is survived by his wife Sue and two children, Roxanne and Jarrod.
Algoa FM News has also been told that there had been a long delay before an ambulance arrived on scene and a longer wait for the state pathology vehicle to arrive on scene.