“The sole occupant [of one of the cars] was passed away by the time I got there and checked for a pulse,” she said.
In the other car the driver had fallen to the ground and was screaming, she said.
“The passenger got out and me and another lady helped her to the floor to lay down.”
She said about four other members of the public also came to help at the scene, working to keep the survivors awake and warm until help arrived.
The two survivors appeared to be in their 20s while the driver of the other car looked to be middle-aged, she said.
One was flown to hospital by helicopter while the other was driven by ambulance.
The woman’s children were in the car when she attended the scene, and the oldest saw some of the aftermath.
“We had a lot of explaining to do to our young children in the car,” she said.
“People need to be more vigilant. So many crashes happen down the straights and these people have families that love them and are expecting them home, so they need to be more alert and focus.
“One wrong decision ruins lives.”
Police confirmed one person had died and two others were critically injured.
The Serious Crash Unit is attending.
Diversions will be in place while emergency services work at the scene.
A local said all he saw at the scene were “lots of flashing lights” and “helicopters”.