Ambulance services were on the scene within minutes, he said.
Barbara Senior, who lived in the block of flats, felt the crash and went outside to investigate.
She comforted one one passenger and gave the person a drink of water.
"They wouldn't come inside out of the wind. There was a man injured and there were ambulances but there were so many people offering help I just came in because there so many people gawping."
Senior said the crash could have been far more serious.
"It's a very busy corner on a Saturday morning. Nobody seems to know exactly what happened. It's quite a strange place to come down the bank and past the letterboxes."
Senior's own car which was parked outside was fortunately undamaged, she said.
Residents were being evacuated soon for safety reasons while the bus was removed. It's believed the building's structure was unlikely to be damaged. Senior, who has lived in the flats for 10 years said nothing like this had ever happened before.
Ritchies director Andrew Ritchie said the bus was on a timetabled route but he did not know which route number yet.
Ritchie said he did not know the cause of the crash and would launch an investigation that would check for driver error or mechanical failure.
"It seems a bit of a strange one. We'll get the vehicle back and have a look at it this afternoon. We've got to treat it seriously, it could have been disastrous."
Ritchie said his main priority was the safety of the people on board. He confirmed the female driver was okay and said some of the passengers walked away from the crash.
The bus would be towed shortly.
An Auckland Council structural engineer had been requested to assess the situation.
Power is out in the area, according to Vector's website.
"For the safety of the public we have turned off the power in this area. Our crew is on the way," a statement on the lines company's website says.
Police are at the scene directing traffic and a tow truck has arrived. Vector is also at the scene.
The driveway to the block of flats is cordoned off with police tape and a police officer is sitting in the drivers seat of the bus.
There is a bus stop at the top of the driveway near where the bus crashed and the vehicle appeared to have fitted through a narrow gap between a bus stop pole and power pole.