A 37-year-old mother killed in a head-on collision in Waikato last night was in the midst of a text conversation at the time, police say.
Her northbound vehicle crossed the centre line and collided with a car travelling south on State Highway 1 at Piarere, north of Tirau, about 10.30pm.
Three young Tokoroa women in the other car, aged in their late teens and early 20s, had to be cut from the wreckage by firefighters and were taken to Waikato Hospital.
They suffered serious injuries but they were not thought to be life threatening.
Senior Sergeant Fane Troy of the Taupo road policing group said an examination of the dead woman's phone showed she had been sending text messages moments before the fatal crash.
"This is a tragic reminder approaching the Christmas period that drivers need to be aware of the dangers of being distracted while driving.
Because of one moment of inattention, Christmas for a number of families will not be an enjoyable occasion."
Weather and road conditions were treacherous at the time due to extremely heavy rain.
The woman had a teenage son, Mr Troy said.
Her name is expected to be released later today once next of kin have been notified.