One person has died and six students were taken to hospital following a crash involving a bus and a train near Palmerston North.
Police this morning confirmed the driver of the bus died at the scene.
This evening the Transport Investigation Commission opened an inquiry into the causes and circumstances of the accident.
There were 40 people on the public bus at the time of the collision - 36 students, three members of the public and the bus driver.
St John says it was notified of a serious crash involving a bus and a train on Railway Road, Bunnythorpe, at around 8.04am today.
Six school children had earlier been transported to Palmerston North Hospital to be treated but police say they have since been discharged.
Ambulance staff had also been assessing 40 patients whose conditions varied from moderate to minor.
"We acknowledge this was an extremely distressing incident for all those involved, including the students and their families and the family and friends of the deceased," police said in a statement.
Ongoing support is being provided and police say WorkSafe has been advised.
KiwiRail has said it is "shocked" to learn of the crash between a bus and a train.
"Our thoughts are with everyone involved," KiwiRail said in a statement.
"Our staff are on site and working with emergency services. We will work closely agencies for any investigation but for now the priority is allowing emergency services to do their job. The level crossing is protected by flashing lights and bells."
KiwiRail says the train driver was the only person on board the locomotive which was travelling from Palmerston North to Whanganui to collect log wagons.
"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.
"We manage a priority list for upgrades to level crossing protection and this location was not on our current plans to install barrier arms.
"The line speed for trains travelling through this area is 80km/h. The driver has told us he was sounding his horn before the collision," KiwiRail says.