Locals are being warned about asbestos risk, after a large fire broke out in a Lower Hutt factory.
Fire crews were called to Chair Solutions on Hutt Park Rd just after 6am by the building's automatic fire alarm.
The fire itself has now been contained, however crews expect to remain at the site for the rest of the day working to extinguish it.
Assistant area commander Nick Pyatt said they arrived to large amounts of smoke.
"The fire rapidly developed into a fully involved building fire.
"We have approximately 15 appliances here. We're attempting to cut the fire off about three quarters of the way down.
"We hope to have it under control in the next hour and then we need to start looking at fire investigation angles."
Pyatt said the fire was categorised as a "fifth alarm", meaning it was quite significant. Between 60-70 firefighters were working on the blaze.
"We've got appliances here from Porirua, all through the Hutt Valley. It's probably about half of Wellington's appliances."
Across the road from the factory fire, City Care workers have been sent home for the day due to the risk of asbestos filled smoke.
Dave Stevens worked at nearby Seaview Engineering, and had also been warned about the risk of asbestos.
He said when he first got to work he saw the top storey of the Chair Solutions factory on fire.
"It's two storey, and all the top is glass. It was just full of flames inside, the roof was starting to catch alight.
"The factory next door as well, the whole roof was alight.
"It's calmed down a lot now but there's still smoke and flames. You can see a lean to it on one end, where it's collapsed down.
"The windows are all burned out and blackened, and downstairs it's all just black.
"It's pretty much munted."
Stevens said they'd been warned to stay back from the building, as there was a danger of asbestos from the roof.
Fire and Emergency assistant area commander region three Brett Lockyer said the main risk now is from the hazards inside the building.
He said there were multiple LPG cylinders and vehicles inside - and asbestos in the roof.
Fire and Emergency has sent out an alert, warning people in the vicinity to close doors and windows, and turn off air conditioning.
If people can smell smoke they are advised to move further away.
They said anybody experiencing breathing difficulties or eye irritation should go to a doctor, or A and E.
The Hutt Valley District Health Board said this advice is especially important for people at higher risk, such as the elderly, children, smokers, and those with heart disease, asthma or other lung disease.
Fire and Emergency shift commander Murray Dunbar said there were no reports of anyone injured or inside the building.
The fire has broken out not far from another blaze at Macaulay Metals in Seaview last week.
The protest will pass over the harbour bridge this morning.