A Bay of Plenty District Health Board spokesman said the patient was a 12-year-old male and was currently undergoing assessment and treatment at the hospital.
Police said this evening one person was in hospital with critical injuries.
The crash happened outside Tauranga Intermediate School.
The school's principal, Cameron Mitchell, confirmed a pupil at the school had been injured.
Mitchell did not see the crash, but he understood the child had been clipped by a car and trailer while walking across the road.
The child had been taken to hospital.
He said the road was now closed and he was working to keep his students safe.
A photographer at the scene said there were diversions in place but there was traffic chaos in the area around the closed section of road, including on Cameron Rd, 17th Ave and Courtney Rd.
Meanwhile, the police national dive squad was expected to arrive at Lake Rotomā this evening after a car was found submerged in the water.
A police spokeswoman said they received a report of a vehicle in the water about 9.45am.
It was not clear how long the car had been there.
The car was found at Ōtangiwai Point - the same spot where two people died in July after their car plunged into the lake.
The cause of Monday's crash has yet to be established, but locals have raised concerns about speed limits in the area.
A man who works down the road from Ōtangiwai Point, who wished to remain anonymous, said it was " a pretty tough corner, pretty sharp".
"There is a metal barrier but there's a car park where you can still go through."
He said some vehicles travelled "quite fast" down the stretch of road in question.
It was scary to think another had gone off the road.
Another Rotomā resident, who did not wish to be named, was sad about the crash and agreed some people sped down the stretch of road.
"The strong message is the 70km/h speed through the area is not causing the cars to slow down enough.
"We need to get it down to 60km/h."
