A Fire and Emergency Services spokesman said three appliances had been called to an incident where a car went off an over bridge onto train tracks off Stadium Dr, just before 7.15pm.

Two elderly people were in the vehicle. A police spokesperson said it appears the male driver may have suffered a medical event, and unfortunately was unable to be revived by emergency services.

His passenger, a woman, was reportedly trapped and in a serious condition.

St John were also at the scene.

Emergency services have called for all trains to be stopped in the interim.

Auckland Transport said the event was impacting Pukekohe Station where platform staff and electronic signs were alerting commuters to expect delays and cancellations.

A witness to the crash said it appeared the car had driven through a fence above the railway track - near the Mad Butcher store.

He said the drop from the road down to the railway tracks was about 15 metres.

He said emergency services have put a total road block in the area.