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Scores of firefighters have put out a fire on the roof of an Auckland CBD high rise which may have started during construction taking place on the building.
Passersby were seen gathering and gazing up at smoke billowing from the top of the building while police controlled the scene.
The roof fire - believed to have started after an explosion during demolition works - has been extinguished.
Fire communications shift manager Dallas Ramsay said about 50 firefighters attended the incident at the corner of Mayoral Drive and Queen St.
"We received a notification of a fire just after 3pm.
"The fire itself is contained to a large metal box on top of the building, the building is possibly under construction."
She was not able to confirm if anyone was in the building.
Fire crews were trying to get water up to the roof to put it out earlier this afternoon.
The former office building is owned by Russell Property Group, which is planning to convert it into a 250-room hotel.
The former office block is being converted into a new Four Points by Sheraton hotel, expected to open this year.
Russell Property Group owner Brett Russell said a demolition subcontractor had been working in the plant room on top of the roof when the fire started.
"From what I believe the demolition guys were cutting something on top of the roof and what they were cutting had a small explosion.
"We're not sure what caused it, they're investigating it now. The fire brigade's there and everybody's safe," he said.
Strong winds are probably making the fire look worse than it is, he said.
"From what I've been told, it's contained on the roof at the plant room. Nobody was hurt, and they think it's under control."
The hotel is still under construction and has no occupants. The company's partners Dominion Constructors is managing the build but its staff were not involved in the incident.
Russell did not believe the fire would delay the opening of the hotel.
Eyewitness John told Newstalk ZB fire trucks have swarmed to the area and police were keeping people away.
He said he's never seen so much smoke.
"It's quite spectacular, just the visual impact of this billowing smoke. It's quite daunting really.
Lucy Caccioppoli was working at theatrecafebar when the fire began.
"Our manager was like 'there's a fire, everyone go look' ... we all went outside and stood there looking and pointing."
She understood the building was being renovated.
"All the businesses that were in there have moved."
Luke Wilson, who also works nearby, heard sirens and then noticed a flurry of activity outside as passersby aimed their eyes and phones in the black smoke billowing from the top of the building.
"We thought, 'what's going on here?'"
Auckland Martial Arts manager Jun Littlewood said those in buildings further away could see more than she could, standing opposite the base of the building.
"I had people ringing me up and saying 'there's plumes of smoke everywhere', but I couldn't see it. My brother-in-law rang from the BNZ Tower and said 'it's just pouring out' ... I was waiting for the glass to explode so we could have a little bit of McGyver going on, I was waiting for some sort of drama, not just black smoke pouring out."
Office worker Adrian Dick said smoke was billowing from the roof but he could no longer see flames.
"There are a couple of firemen on the roof with a ladder. They're just underneath where the smoke's coming out, probably trying to get it under control."
Motorists are being warned to expect hazardous driving conditions.