A Hato Hone St John spokesman said they were notified of the incident at 1.05am.
“Two ambulances, one rapid response unit, two helicopters and one operations manager responded.”
Two patients in serious condition and another in moderate condition were airlifted to Waikato Hospital.
Munn said fire services assisted with patient care until the ambulance arrived. They left the scene at 2.25pm.
The police spokesman said three people were reported to have received serious injuries and SH1 was temporarily closed, reopening about 3.40am.
Eva de Jong is a reporter for the Whanganui Chronicle covering health stories and general news. She began as a reporter in 2023.