The third passenger, understood to be an 8-year-old girl, was in a moderate condition last night.
Mr Brettkelly said the children both had head injuries.
The two rescue helicopters - Rotorua BayTrust Rescue Helicopter and the Tauranga-based TECT Trustpower Rescue Helicopter - were unable to reach the crash site due to bad weather and landed at Opotiki Airfield.
The crash victims were lifted by rope out of the river bed and taken by ambulance to Opotiki and flown to hospital from there.
The car involved in the crash was a small hatchback which crashed 15m down a steep bank into the river.
Mr Brettkelly said the car had left the road, flipped and landed in the river on its wheels.
The crash happened just after 11am and the crash victims reached hospital around 4pm.
"The vehicle went off the road and into the river," said BayTrust Rescue Helicopter pilot Art Kowalski.
"It was meant to be a winch job but we couldn't get in to the gorge because of the bad weather."
Police were told a woman was trapped and unconscious in the partially submerged car and that two children had escaped.
The police serious crash unit will be investigating.
