The exercise was organised by local police, fire and St John ambulance, with support from Horizons Regional Council. Cleveland Funeral Home was also involved, and local schools were invited to send their students to watch.
Tamara Stratton from SADD said the purpose of the mock crash was to show students the reality of what happened during a serious crash.
"We hope that by seeing this, they'll be aware of distractions that can happen during driving. Hopefully they'll never have to experience this themselves."
Tamara said SADD held a mock crash every few years.
"We don't do it very often so that it's fresh and unexpected for the students."
For Jovanna and Pita, the mock crash had been frighteningly real.
"I was in the back of the ambulance and I saw them taking out Caleb, and he looked really dead," Jovanna said.
"It was very scary when the firemen told us they would have to cut us out of the car," Pita said.