One moment Woodville Primary School principal Keith Riddles was going through his daily teacher briefing, and the next he was standing over the bloodied body of a father, who was shot dead doing the school run on Wednesday.

"What we thought was a car backfiring, turned out to be gunshots," Riddles said after a tough day of keeping everybody calm.

"We soon realised it was... not just two or three, we saw 16 bullet shells on the ground," he said.

The teacher said the dad had been shot dead just before 08:00 during the drop-off crunch.

"Parents were bringing their children to school. Taxis were dropping children off," he said.

"One of our fathers was dropping his son, who is in Grade 2, and his two nieces, who are in Grade 6.

"As he got out with the children and was about to cross the road, these gangsters came and then pulled their guns out."

Riddles said children from Grades R to 7 saw the shooting, but fortunately none were caught in the crossfire as the dad's body was riddled with bullets.

"It was pandemonium," said Riddles. "But it could have been worse."

They got the children into the classrooms and had to take the teacher in charge of scholar patrol, who was close to the shooting, to a doctor because she was so traumatised.

"She was a wreck," he said.

On Thursday, a school psychologist and the Mitchells Plain police's Victim Support Unit will start counselling everybody. The local community policing forum has also offered to assist.

"It's been quite traumatic. But you have to keep your own strength and stability as the manager of the school."

Police are investigating the shooting.