The car came to rest upside down at the bottom about 8.45am.
Wanganui firefighters were called to the scene because they are a specialist line rescue crew, and two of the team made their way down to the car.
St John Ambulance spokesman Ian May said a 17-year-old girl with moderate neck injuries and a 29-year-old man with moderate arm injuries were taken to Whanganui Hospital by ambulance.
The Palmerston North rescue helicopter was called to winch the patients out.
Base manager Chris Moody said the most seriously injured patient - an 18-year-old male passenger from Bulls - was hoisted in a stretcher as he had suspected spinal injuries. He was airlifted to Palmerston North Hospital.
"They were lucky to survive the fall," Mr Moody said, adding that the other two occupants were from Marton.
Mr Weston said the car was still in place yesterday afternoon and police were working on how to get it out.
As well as two Wanganui fire trucks, crews from Mangaweka, Hunterville and Taihape attended the crash, plus police, ambulance, and the rescue helicopter.
"It was a good job, all the services worked together," Mr Weston said.
"It could have been so much worse for those young people."
Mr Burmeister said three charges were being laid, one of which was dangerous driving causing injury.
