A baby remains in a critical condition after a crash near Cambridge that's believed to have killed both his parents.
The crash, which happened on Cambridge Rd in Leamington about 6pm on Saturday, involved a ute and a logging truck.
Claire Allen and James New were among the first people to arrive at the scene of the crash, and told Stuff they saw a baby boy being pulled from the car, still strapped into his car seat.
"He was crying, it was very weak, but hearing the cry was so comforting," Allen told Stuff.
"It was scary and there was blood everywhere but he did seem okay. He started off well but then I think he started going into quite a bit of shock."
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When fire crews arrived it had become clear the baby's parents were dead, she told Stuff. It had been raining heavily just before the crash.
"I've always been huge on car-seat safety, but [the seat] really did save the baby's life. It was in perfect condition," Allen said.
Local Gavin Collinson earlier told Stuff the crash had happened just after the ute rounded a notoriously dangerous corner, meeting the logging truck travelling in the other direction.
A Waikato District Health Board spokeswoman said on Sunday evening that the baby remained in a critical but stable condition in the hospital's intensive care unit.
The police serious crash unit is investigating the incident, which is part of a spate of four crashes that have killed five people in the Waikato over the weekend.
On Saturday morning at 10.30am a person died in a two-vehicle crash in Tahuna, 18km north of Morrinsville, while on Saturday night a person died when their vehicle crashed into a power pole on State Highway 25 near Pipiroa, 15km southwest of Thames.
A horror crash in Northland early on Sunday also killed three people - reportedly all from the same family - while a child was critically hurt. The crash happened at 2.15am when a car smashed into a tree near Whananaki.
The weekend's crashes have brought this year's road toll to 49 - still three lower than this time last year.
Police are still investigating the causes of those crashes but with rain widespread across the North Island for the first time in a month, slippery roads likely added to the danger.
Drivers were warned to be careful this weekend as the much-needed rain risked bringing deadly "summer ice" to the roads, particularly in the Waikato and Bay of Plenty.
System manager Rob Campbell encouraged motorists to take care.
"After an extended run of warm, dry summer days like we've had, any rain can result in slippery road surfaces, otherwise known as summer ice.
"Even a very small amount of rain can make the roads very slippery. In fact, it can be more hazardous than heavy rain because grime and exhaust particles that have built up on the road take longer to be washed away," Campbell said.
"The combination of light rain and summer grime creates a slippery film on the road."