Family’s agony after daughter, 11, is killed in boat accident

The family of an 11-year-old girl killed when she was thrown from a banana boat at a friend's party are "utterly devastated", relatives said today.

Mari-Simon Cronje's parents paid tribute to their "beautiful daughter" after the freak accident at a watersports club near Feltham, west London, on Saturday afternoon.

The girl is thought to have been hurled into the air and smashed into the back of the speedboat which was towing the 20ft inflatable. The tragedy happened when the boat took a sharp turn.

Today parents of Mari-Simon's classmates at Ibstock Place School, near her family's £1 million home in Barnes, spoke of their shock.

One parent, who did not want to be named, said: "My sons were good friends with her. Since they found out it's like they've been walking around in a coma.

"All the children are devastated. She'd been at the school for two years so everyone knew her. All the children have been on Facebook all weekend discussing what happened. One of my children had a party at the water park six months ago. It all seemed safe, it seemed totally fine there. The 10 girls who were on the boat with her must be finding it so hard.

"How do you ever get over seeing your friend die at such a young age? The school are holding a special assembly today and counsellors have been brought in."

The family were too upset to speak at their home today. A close relative said: "They are utterly devastated. It's an impossible time for them, they just want to be left alone now. It was a school friend's birthday party and they weren't even there when it happened. They are now leaving it to the police to investigate."

Mari-Simon, the daughter of City financier Andries Cronje, the chief executive of UBS Wealth Management, was airlifted to West Middlesex Hospital where she died.

There are reports that only the driver was on the speedboat and that there was no "spotter" – someone else watching the participants in case of problems.

The Princes Club in Bedfont, which closed after the incident to allow an investigation to be carried out, said in a statement: "Princes Sporting Club and everyone associated with it is devastated by the accident that occurred on 11/9/10.

"At this terrible time our thoughts and deepest sympathies are with Mari-Simon Cronje's family and friends."