A parenting expert says it's difficult to prevent teenage tragedies because they haven't learned how to mitigate risk.
Five boys aged 15 and 16 died after the overloaded car they were in lost control and smashed into a power pole in Timaru.
It's likely alcohol and speed were factors in the crash.
The 19-year-old driver suffered serious injuries and is in hospital.
Nathan Wallis told Mike Hosking parents can put boundaries and support around kids to try and avoid things like this.
"It's never an exact science. Kids go off the rails as teenagers and they do silly things. It's just this time it's ended in tragedy."
Wallis says that scaring teenagers by showing pictures of crash scenes doesn't work because they don't think it'll happen to them.
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