Emergency services were called to the two-vehicle collision on the Napier-Taupo Rd, between Tataraakina Rd and Pohukura Rd, about 9.52am today.
The van, one of a convoy of three travelling north, had moved to the left of the road before attempting to turn right into the Tarawera Cafe and crashing into the oncoming truck.
Both vehicles left the road and dropped down a 15 metre bank, where the mangled remains of the leaking truck stayed throughout the day.
Hawke's Bay Senior Constable and serious crash analyst Tim Rowe confirmed one person died at the scene and said it appeared to have been caused by a "momentary lapse in concentration".
In the van were 10 Samoan workers who were a part of the recognised seasonal employer scheme, and one New Zealander. All were on their way to a Taupō for a holiday.
Hawke's Bay road policing Acting Sergeant Nathan Ross said one passenger in the van, in their 30s, had died and the other 10 were in varying states.
The truck driver was uninjured.
"Two vans managed to pull into the café, but the third was involved in a vehicle collision. Police are working with the Samoan council to inform their families," Ross said.
"State Highway 5 is one of the deadliest highways in New Zealand," Ross, who noted it was drizzling at the time of the crash, said.
"Unfortunately, a lot of it comes down to driving behaviour. It's a sad day for all the families of the people involved and for the first people at the scene."
The highway has reopened.
The scale of injuries from the crash forced emergency services to spread the victims around North Island hospitals.
A St John spokeswoman said five people were transported to Hawke's Bay Hospital - one critically injured person was airlifted and one with serious injuries and three with moderate injuries were taken by road ambulance.
A Hawke's Bay District Health Board spokeswoman said a male teenager remained in a critical condition in intensive care on Monday afternoon.
Four more men, two in their 20s, and one in their 30s and 40s, were in a stable condition.
A man in his 40s in a critical condition was airlifted to Gisborne Hospital. He was in a stable condition this afternoon, a hospital spokesperson said.
Two males flown to Palmerston North Hospital were in a stable condition. Another person in a serious condition and one person in moderate condition were transported to Taupo Hospital by ambulance.
One person had also been taken to Waikato Hospital, Ross said. Their condition was not immediately available.
A police spokeswoman said an investigation into the crash was under way, but it was still too early to speculate on what may have caused it.
"Road deaths are not just numbers, and as police officers we never lose sight of the real human loss and grieving behind every death on the road," the spokeswoman said.
"Our thoughts are with the families and friends of all of those involved following this tragedy."
A Fire and Emergency New Zealand spokesman said three fire trucks - two from Napier and one from Bay View - attended the crash.
