Three people involved in a crash on the Napier-Taupo Rd remain in hospital on Thursday morning.
A woman in her 40s and two boys were in a stable condition in Hawke's Bay Hospital about 8am after the crash near Te Haroto on Wednesday evening.
A fourth person injured, a man in his 50s, was discharged overnight.
Emergency services were called to the crash, a vehicle that hit a power pole knocking down power lines, about 4.40pm.
The Hawke's Bay Rescue Helicopter transported one person to hospital while the other three went by St John ambulance.
The road was fully closed for four hours, with vehicles at both ends turned back, and did not fully reopen until just after 3.30am.
Conditions on the road at the time of the crash were dismal, with rain turning to sleet overnight.
It continues a run of serious crashes on State Highway 5, a part of the Thermal Explorer Highway.
Eight deaths have already been recorded from five separate crashes on the road from December 2019 to June 2020.
A week ago 10-year-old Teang Atauea died in Hawke's Bay Hospital after a crash in a nearby stretch of the road on June 23.