"Red flames were coming up from the roof - the firefighters were fighting relentlessly with their hoses, but now it looks like the fire is stuck in the ceiling under the roof."
Two hoses were being pointed at the building, flooding it from Victoria St, while firefighters were moving in and out of the building.
"They've stopped cars coming through. They're still letting pedestrians walk through...there are at least 200 people standing on the opposite side watching and filming."
Emergency services looked like they were extending the cordon along London St, Preston said.
None of the surrounding shops were open today and it appeared nobody had been evacuated.
The smoke now seemed to be subsiding as firefighters brought the blaze under control.
Fire and Emergency NZ northern shift manager Kaisey Cook said FENZ was called at 2.50pm to reports that pallets were on fire against the two-storey building.
"When we got there our crew started to put it out, however it had gone into the roof of the building. We had to force entry to the building."
Cook said the fire was classed as a "third alarm" and five appliances plus an aerial were on scene, with a seventh en route.
The building is 50m x 20m and is unoccupied. The roof is well involved, Cook said. She could not confirm whether the building was attached to other buildings.
An ambulance has also arrived at the scene, with the river end of London St now blocked off.
Traffic is building heading south on Victoria St.
The building was the site of Munn's menswear but is currently empty and for lease.
Firefighters are setting up a Hazmat command unit on London St. Photo / Belinda Feek
