Three best friends aged in their early 20s died after their car burst into flames when it crashed into the side of a large truck and trailer parked on the side of the road.
As a result of the collision on Cambridge St in Levin, the car exploded into flames, engulfing the car and the truck at 12.20am.
Police said the occupants of the vehicle died as a result. Nobody was in the truck.
Maureen Devereux, who was working at Bassingers Motor Lodge on Oxford St in Levin, said the flames were so huge she and her husband initially thought a house had caught fire.
"We heard three explosions at about 12.30," she said.
The couple woke this morning to find ash all over the motel's forecourt.
Devereux said her husband went out to see what was going on as soon as they heard the sounds, but by the time he arrived he saw there was nothing he could do.
Emergency services were on the scene when he got there, she said.
"It's terrible for Levin."
Levin mayor Michael Feyen said the situation was "extremely sad".
"I really feel for the families."
Feyen said he understood those who died were young people, but couldn't comment further until he received further information from police.
Police said they were working to confirm how many people were in the car at the time of the crash.
But the Herald understands three young men were inside, including two who had been friends for several years and the brother of one of the men.
They all lived locally.
It is not yet known where they were heading or who was driving but the owner of the car has been described as a "really nice guy" who was well-liked by the company he worked for.
Family were called by police overnight and arrived at the scene to see the road blocked by police, and the car wedged under the truck, covered by a tarpaulin.
A reporter at the scene this morning said the truck appeared to have been carrying commercial rolls of paper, which were now strewn across the road.
It was a sunny day in Levin following a cold night with no rain, she said.
The truck's body was burned out, its tyres were blown and the entire vehicle was badly damaged. Officials were preparing to move it at about 10am.
About 20 locals were at the scene this morning but none appeared to be relatives or friends of those in the car.
Central fire communications shift manager Mike Wanoa said the incident was initially reported as a rescue so they sent two crews.
When it became evident there was a fire they sent two more crews and put the fire out.
Levin residents reported hearing an explosion at the time of the collision.
Levin resident Charles Bagnall said the truck had been parked on Cambridge St for several weeks without moving.
When he passed it on his morning walk about 8am he saw the middle had been badly damaged.
"The car would have driven straight into the side of it," he said.
"The tarpaulin has been burned and there's rolls of some sort of material which has been partially burned as well."
The Police Serious Crash Unit and other specialist staff are in attendance and the cause of the crash is being investigated.
A car also crashed in Otorohanga around 5.30am this morning.
The car rolled on State Highway 3 and blocked the northbound lane. No one was injured and the vehicle is now off the road.
Wayne Dewes died in hospital from severe injuries.