Late on a summer afternoon a big rotating thunderstorm dropped a tornado on Vaal Marina, a lakeside settlement south of Johannesburg. In a track of about one and a half kilometres it destroyed hundreds of homes, and around fifty people were hurt.
▶ Open on the mapThe parent storm lasted seven hours and travelled hundreds of kilometres across the Highveld, also dropping large hail.
The Vaal Dam next door is one of South Africa's biggest reservoirs and a favourite weekend spot for boats.