The wreckage has been cleared from the crash site where four teenagers were killed in Invercargill on Queens Drive just before 4pm Friday.
Mike Bowman, Southland Area Commander, said that the crash was between a Ford Ranger and a concrete truck.
Three of the victims were 16, and one was 17.
A red rose and some yellow lillies have been placed on the side of the road and a note reads, "rest in love boys, forever grateful to have known you all."
Bowman said police were still investigating the cause, and that it was a "tragedy" for the families.
The truck driver suffered minor injuries.
"It was a horrific scene ... It's a tragedy for any family to have to go through this," Bowman said.
Bowman said the victims' families have been brought to the scene to grieve, and staff are shaken.
The names of the victims will not be released today, Bowman said.
He said three of those dead were from Bluff.
"It's a tragedy for the Bluff community as a whole as you can imagine. The Bluff community is a tight community and this will have a huge impact."
Bluff Community Board chair Raymond Fife told RNZ they came from well-known families and he is distantly related to one of them.
"They're all devastated. It is a tragedy.
"The community will rally around those people and give them as much support as possible, because Bluff is a small town."
"They're people that have lived in Bluff their whole lives ... They've got children that have grown up in Bluff and supported Bluff."
Fife had not yet spoken to the families directly but intended to.
"It's important to give them that time to grieve at the moment."
Invercargill Mayor Tim Shadbolt said it is heartbreaking.
"It's just so devastating to hear. It's a small, tight-knit community and there's going to be a lot of suffering and sense of terrible loss."
Shadbolt said he does not know the specifics of this crash but there have been others there recently.
He said it seems unusual the crash was on a straight road, but it had been wet.
"There's been several crashes or near-misses because of the road conditions and other issues that'll come out."
Fire and Emergency New Zealand said people were trapped when crews arrived at the crash and the roof of one vehicle was cut off.
Police want to speak to witnesses. Anyone with information is asked to contact police on 105 quoting event number P050332364.
Information can also be passed on anonymously through Crime Stoppers on 0800 555 111.