The driver of a school bus involved in a crash with a train near Palmerston North this morning has died.
Emergency services were alerted to the serious crash just after 8am at the intersection of Railway Road and Clevely Line in Bunnythorpe.
St John said it assessed 40 patients at the scene, including Feilding High School students, whose conditions varied from moderate to minor.
Seven people were brought to Palmerston North Hospital's Emergency Department, all in a stable condition, with two being admitted to a ward for observation and the rest discharged.
MidCentral DHB's Lyn Horgan said the hospital has also provided space for family and friends, and is offering pastoral support.
Following the collision, staff from Feilding High School came down to provide support to the children.
Four ambulances and a rapid response team were sent to the scene.
Three investigations have now been set up and police senior sergeant Phil Ward said a number of different agencies were now following up.
The Transport Accident Investigation Commission has opened an inquiry into the causes and circumstances of the collision.
Acting chief investigator of accidents Naveen Kozhuppakalam is appealing for anyone with information to come forward, especially any motorists with dash-cam footage.
Kozhuppakalam has appointed two investigators, who will first inspect the train and the bus, map the site, examine rail systems and vehicle components, seek any recorded data from the vehicles' electronics, and obtain maintenance records.
"They will also interview the train driver, other staff, and any witnesses to the accident."
The response of the staff at Palmerston North Hospital was praised by the chief medical officer for the Midcentral DHB.
Dr Kelvin Billinghurst said they were given advanced warning that the accident had happened, and set about preparing for an influx of patients.
He said they cleared the Emergency Department, and prepared for an unknown number of casualties.
"I must commend the staff - they performed really admirably according to the processes that have been really well established in this institution," he said.
Parents who wanted to collect their children were asked to make themselves known to an officer at the scene.
In a statement, KiwiRail chief executive Greg Miller said the company was shocked to learn of this morning's collision, and had sent staff to work with emergency services.
The level crossing is protected by flashing lights and bells - but the mayor of the Manawatū District, Helen Worboys, said it was one of several high-risk areas where roads intersected with rail.
The train driver is physically unharmed but shaken by the incident and was being supported by staff on site, Miller said. He was the only person onboard the train, which was heading to Whanganui to collect log wagons.
There was minor damage to the train, Miller said.
"In the last 15 years there have been no collisions at this crossing between trains and either vehicles or pedestrians, although our records show one near miss when a car crossed in front of a train in January 2011.
"The driver has told us he was sounding his horn before the collision."
The North Island main trunk line is closed between Marton and Palmerston North.
Three freight trains were being held back while the line is closed, Miller said.
The site of the crash had been blessed and police said the road was expected to open shortly.
In the meantime, diversions were in place and motorists were asked to avoid the area.
WorkSafe had been advised and an investigation into the cause of the crash is ongoing.