An investigation into the cause of the crash was ongoing, Mr Fleming said.
Police said the van had plunged 40m down a bank, however a spokeswoman for the Lowe Corporation Rescue Helicopter, which was involved in winching passengers to safety, said the drop was 10m.
The helicopter spokeswoman said the driver of the van had fallen asleep.
A man and the baby were thrown free from the van, but the man, who had serious injuries, was able to climb to the road and alert a passing motorist.
The remaining six people were trapped and had to be removed by emergency services, and then winched to the road by helicopter.
Three rescue helicopters were dispatched to help with the rescue, with the Lowe Corporation chopper winching four passengers from the scene, and airlifting a woman and girl with spinal injuries to hospital.
The Greenlea Rescue Helicopter from Taupo took the six-month-old baby and a 22-year-old man to hospital, and winched out the remaining two passengers.
Greenlea pilot Nat Every said the baby had multiple traumatic injuries, while the man had neck and upper back injuries.
Mr Every said there were several obstructions for the winching operation, including trees and power lines.
The Bay Trust Rescue helicopter from Rotorua also took one patient to hospital, while a further three people were taken by road ambulance.
The road was closed for several hours as the trapped people were rescued.
Jim Andrew from the Tarawera Cafe, on the Napier-Taupo Rd, said traffic backed up for about 1km on each side of the crash scene.
His cafe, about 3km away on the Taupo side, was "full up" with stuck motorists, he said.
A Hawke's Bay Hospital spokeswoman said this afternoon the baby boy, a 12-year-old girl and a man in his 30s were in critical condition in the Intensive Care Unit.
A woman and man, both in their 30s, and a girl, 9, had been moved from general wards into the High Dependency Unit, and were all in serious condition.
Two men, one in his 20s and one in his 40s, were in stable condition in a ward.
