Denise Wilson, who saw emergency services attending to the victims from her Totara Rd house, said the scene was "horrific".
"It's just horrific ... and this comes after several other fatal accidents we've had."
On Sunday afternoon one person died in a three-car crash on Great South Rd in Auckland. Another person was taken to Middlemore Hospital with moderate injuries.
Yesterday morning a man was found dead after a car crash in Southland.
Police received a report about the crash at 6am, but believe the crash may have occurred several hours earlier, some time after midnight.
The vehicle left the road and crashed into a fence on the Tuatapere Orepuki Highway (State Highway 99), south of Jenkins Rd.
The Serious Crash Unit is investigating the accident.
Over Labour Weekend last year, six people lost their lives on New Zealand roads.
Across the country 126 people were injured in crashes over Labour Weekend. Three of those killed and eight seriously injured were in the Auckland region.
Police national road policing manager Superintendent Steve Greally urged drivers to keep safe on the roads.
"Drivers can keep themselves and others safe by paying attention to their driving and surroundings, driving to the conditions, never driving impaired and always wearing their seatbelt," Greally said.
"We know the four main behaviours that contribute to death and serious injury on our roads are people driving distracted, drivers impact by fatigue, drugs or alcohol, drivers speeding and people not wearing their seatbelt."