KEY POINTS:
A blaze that brought Queen St to a standstill last night was caused because a dirty air vent covered in "fat and grime" caught fire, a Fire Service spokesman says.
Up to 86 firefighters, police and ambulance staff flooded Auckland's main street, which was cordoned off from Wyndham to Custom Sts from 5.20pm.
Dozens of spectators watched, taking photos on cameras and mobile phones, as firefighters on extension ladders were lifted to the second storey of the building to get to the blaze and make sure no one was in the building.
Smoke from the fire billowed out into nearby offices, sparking the evacuation of several high-rise buildings.
The basement of the nearby Herald building was 1m deep in smoke.
Fire Service northern communication centre spokesman Steve Smith said early reports of people being trapped in the building were not correct.
"Our only fear was that there may have been someone in there we didn't know about and that's why we went in."
Mr Smith said the threat to nearby office buildings led to the massive response, which at one point took 28 Fire Service vehicles, including 14 fire engines.
Auckland Fire Service promotions and education spokesman, Senior Station Officer Mike McEnaney, said the fire began in the vent above the kitchen's cooking plates when flames hit a build-up of fat and grime above.
"There wasn't a grille installed in the ducting area above the cooking plates," he said.
"If they've got the proper grilles installed it shouldn't be a problem. The lesson learned here is to have the right safety features and clean grilles in commercial kitchens.
"We'll certainly look at talking to management about ensuring they've got the correct safety gear and ensuring that the ducting's cleaned and maintained on a regular basis."
No one from Burger King was able to be reached for comment last night.
