Jack said he'd learned about tilting someone's head back to open their airways.
"I had a suspicion that it was fake."
While the make up was "incredibly well done", Jack couldn't help but notice everyone involved in the scenario was a prefect.
Horizons Regional Council Roadsafe co-ordinator Glenda Leitao said the idea was to show students what happened in these types of situation.
"The kids rang me and asked, 'can we do a mock car crash'," Ms Leitao said.
"It's quite easy to do," she said. The school requested no fatalities, but had some students appear to be injured, and had police breathalyse and arrest the driver.
Mr Dudley, Wanganui's fire risk management officer, said firefighters and St John paramedics would work together to assess and free the occupants of the vehicle.
As students gathered around the scene, some looking confused or concerned, others grinning, drama students spoke to people through the smashed car window and called emergency services.
"What are you looking at, man? Help!" one student yelled at bystanders.
Mr Dudley got on the microphone explaining what students should do if they came across a car accident.
"I've you've crashed 10 minutes out of town, what's going to happen?" he asked the crowd.
"They could be bleeding to death."
Horizons transport manager Phillip Hindrup said it was "sobering" to think how long it could take emergency services to reach an accident "when it's you in the car".
Year 13 student Jay Duggan waved down fire trucks and ambulances as they came in, sirens blaring.
"I've been to situations like this before," said Jay, who had witnessed a car accident only a few weeks earlier and had been first on the scene.
Jay said instinct and "first aidness" kicked in.
"It just opened my eyes as a young driver. You can never be 100 per cent in control of a car."
Freya Ewing, 17, was involved in organising the scene as head of the community group. Students had seen another mock crash at Wanganui Collegiate, and decided they should set one up for their school.
Sergeant Colin Wright of the road policing team said they also wanted to show teenagers exactly how drunk drivers were dealt with.
"If they're involved in a crash and they had alcohol in their system they would be dealt with by police."