Although the crash happened on a straight stretch of road, the local man said it wasn't known for speeding. Accommodation provider Lynn Robinson was rocked to hear the crash so close to her home was fatal.
"It's just tragic. It's devastating."
She said the crash was just beyond a sharp bend that had only recently had its speed limit reduced to 80km/h because of the high number of smashes over decades.
The stretch of road where it happened was known to be the only place for some distance - north or south - where cars could pass.
"All the fast drivers and trucks know that's the place to pass but it's a blind corner and you've got to time it just right."
UPDATE: 5:30 PM
Motorists are advised to delay their journey or consider using an alternate route for travel between Kaikoura/Christchurch to Blenheim. Detour Route: Northbound travel use SH7, SH65, SH63 and SH6. Reverse for southbound travel. ^JPhttps://t.co/hXnhPXXLxC
— Waka Kotahi NZTA Canterbury & West Coast (@WakaKotahiCWC) December 6, 2019
Robinson said locals would be on tenterhooks waiting to find out if they knew the dead people.
Robinson was also expecting guests. "I'm waiting for a family of three. I just pray it's not them."
She said two air ambulance helicopters had now landed on State Highway 1. Traffic was being diverted along a narrow coastal track to loop around the crash.
Police said State Highway 1 will stay closed while they remain at the scene.