"The female passenger of the vehicle was ejected from the vehicle and died at the scene."
The ute's driver was taken to Wairarapa Hospital with serious head injuries. Mrs Watson said it was "miraculous" he survived.
"It's amazing that anybody survived with the damage to the ute."
The incident happened just off State Highway 2 between Masterton and Carterton at 8.10am, at a crossing controlled by a stop sign but with no lights or barrier arms.
The southbound Masterton to Wellington train, travelling about 90km/h, activated its emergency brake and took 510 metres to stop.
Traffic Sergeant Chris Megaw said there was clear visibility to the north, from where the train was approaching.
The car, travelling east towards the highway, hit the right-hand side of the train a few metres from the front, puncturing the train's fuel tank and causing a leak.
"The impact was on the left-hand side of the car, and the impact has ripped the tray off and sent it spinning to the side," Mr Megaw said.
The fire service was called out to deal with the diesel leak.
The Serious Crash Unit has begun an investigation, which is likely to take several days.
The ute was removed yesterday afternoon.
"It will be inspected by our independent vehicle testing people over the next two days," Mr Megaw said.
Police would be inquiring into whether the driver held a full licence.
About 40 passengers waited for an hour and a half on the train before being taken by bus to Wellington.
The train driver was not injured.
Police had cleared the site by about 3pm, in time for a 4.30pm southbound train.
A KiwiRail spokeswoman said the crossing had a stop sign to warn vehicles. She said there were "a number of [uncontrolled] level crossings around the country".
"Our criteria for assessing level crossings, and whether or not they need more protection than a stop sign, we would take into account the amount of road and rail traffic travelling across those level crossings, the number of rail tracks to be crossed and if the view of the trains would be obstructed."
She did not know if the incident would prompt a review into the crossing's safety.
In an earlier incident, Sheena Louise Wright, 41, died in a collision with a train in Christchurch early on Saturday.
