A child has been flown to Starship Hospital in a critical condition, after a train and car collided near Pukehina this morning.
Emergency services were called to the scene on Duncan Lane around 8.30am.
A police spokesperson says two others have moderate injuries and one person has minor injuries.
All injured were occupants of the car.
Police are investigating the serious crash.
Anyone with information about the crash is urged to contact their nearest police station.
Alternatively, information can be left anoymously via the Crimestoppers 0800 555 111 line.