Getrude Mankaba was driving with her colleague Siphesihle Zola Zuma on the N3 freeway when she noticed stones in the middle of the road.

"I slowed down to drive around them and heard a bang in the car," Mankaba testified.

She drove a little further before stopping her car to check if it had a puncture. She found nothing wrong with the car's tyres, but saw a hole in the windscreen and that Zuma had been injured by a concrete slab that had smashed into the car. Zuma died.

The colleagues had been driving back from a work function on the evening of November 2, 2010.