Three women aged under 20, including a high school student, died in the crash in central Hawke's Bay yesterday.
Silver Fern Farms has confirmed that the three were all employees of its business.
They died after their car collided with a truck on State Highway 2, near Takapau.
The driver of the truck is now in a stable condition after being airlifted to Hawke's Bay hospital.
The agricultural company, which has a meat processing plant at Takapau, said it was "saddened" by the news and was supporting the families and employees.
The Tararua district mayor Tracey Collis said support teams are in place around the district.
The workers were also current or former students of Dannevirke High School.
In a post on Facebook, the school said it was devastated by the tragic deaths.
"[It] has been felt deeply throughout the school community by students, teachers and whānau.
"Our heartfelt sympathy goes to the whānau's and our wider community."
Central Hawke's Bay Mayor Alex Walker said there had been been several accidents in that area in the past.
"This part of State Highway 2 across what we'd call the Takapau plains is notorious and it can be a very dangerous place."
In the past a number of accidents had happened there during the busy Christmas season, she said.