Passer-by administered CPR to bus driver who crashed after 'medical event'

A bus driver remains in a critical condition after a bus crashed into a pole on a busy road in the Auckland CBD on Wednesday.

The crash took place on Mayoral Dr about 7.35pm after the driver suffered a "medical event" while driving.

Auckland Westpac Rescue Helicopter Trust spokesman Lincoln Davies said witnesses saw the driver become unresponsive while driving the bus at a low speed.

"It was noted the bus came to a standstill - a bystander initiated CPR that was continued by our Intensive Care Paramedic and HEMS Doctor on arrival at the scene using the Rapid Response Vehicle.

"The patient was transported to Auckland City Hospital in a critical condition," Davies said.

The driver is employed by NZ Bus and a spokeswoman for the company said all the staff were "very sad and concerned about him".

"It was a medical event, I'm not sure exactly what happened but he's still in a critical condition in hospital - we've been in contact with his next of kin," she said.

Auckland Transport spokesman Mark Hannan said none of the 10 passengers on the the red CityLink bus were injured.

A witness at the scene said the bus looked to be turning from Mayoral Dr onto Greys Ave when it hit a pole on the corner.

Fire, ambulance and police were all at the scene and a screen had been put up to block people's view of the accident, she said.