Serious crash closes State Highway 1

The Auckland Westpac Rescue Helicopter crew are treating a male patient who is in a critical condition. Photo / Auckland Rescue Helicopter Trust

Two people are in a critical condition, and three others have moderate injuries after a three-vehicle crash on State Highway 1 north of Puhoi.

One of the critical patients was trapped in a vehicle, and seven fire engines were at the scene, a Fire Service spokesman said.

The serious crash investigation team is at the scene. Photo / Supplied

One critical patient, a male, was flown to hospital by the Westpac rescue helicopter.

The serious crash investigation team is at the scene.

Police at the scene. Photo / Hayden Woodward

Emergency services were called to the scene about 11.20am and the crash occurred between Cook Rd and Mahurangi West Rd, north of the Puhoi turn-off.

Helicopter emergency medical service doctor, Inia Raumati, was part of the crew on board the Auckland Westpac Rescue Helicopter.

He said multiple cars were involved in the crash.

A man in his 80s was trapped inside his car and had to be cut out by the fire service, Dr Raumati said.

He said the man was the sole occupant in the vehicle, and it appeared he may have had an "event", as he was allegedly driving erratically and crossed the centre line.

Dr Raumati said the elderly man was transported by rescue helicopter to Auckland City Hospital in a critical condition.

He said other patients were taken by St John Ambulance to hospital, in moderate conditions.

NZTA says motorists should expect delays and follow emergency services' directions.

Update: SH1 is CLOSED north of Puhoi. A detour is in place, which will add at least 60mins to your journey. ^LC pic.twitter.com/RXfTprgwht

— Waka Kotahi NZTA Auckland & Northland (@WakaKotahiAkNth) August 20, 2015

On-ramps to SH1 heading north are closed at Silverdale, Grand Drive and Hibiscus Coast Highway.

A detour has been put in place which will add at least one hour to northbound travel.

Paul Nicholas was heading south when the crash occurred.

"Twenty seconds earlier and that could have been me," he said. "The cars were pretty mashed."

The cars collided on one of the last bends before the Puhoi exit, Mr Nicholas said.

One car caught fire, but the blaze was soon put out, he said.

Emergency services arrived within 10 minutes.

Today's crash was about 50m from where a motorcyclist died in a head-on collision with a car last weekend.