A fire which broke out in a conveyor belt system running across the 40m high ceiling of a fertiliser plant in Pandora yesterday led to firefighters battling the blaze as embers rained down on bins of fertiliser materials below.
"The only access to the fire was through the roof but it was too risky to put people in there," Fire Service area commander Chris Nicholl said.
"We went to an external defensive attack."
The fire at Ravensdown's fertiliser plant in Severn St was first spotted by staff at a neighbouring firm who raised the alarm just after 11.30am.
A short time later fire crews were at the scene and were confronted by the uncertainty of what materials were stored inside and the logistics of getting at a fire which was so high off the ground.
Ravensdown communications manager Gareth Richards said the four staff at the plant "stuck to the drill" and evacuated the building and then ensured firefighters received a complete list of materials inside.
"And those firefighters did a great job - they contained it very quickly."
Among the materials stored were the fertiliser ingredients potassium, potash rock and ammonium sulphate.
While inert in the way they were stored, the danger that they posed should they have started to burn, kept the firefighters cautiously at bay.
Mr Richards said the building had a 10,000-tonne capacity but only about 7000 tonnes of material was stored at the time of the fire.
While confined to the ceiling area, he conceded there were concerns over falling pieces of flaming plastic.
"You can never tell in these situations - which is why we constantly have drills in the event of this sort of thing happening."
Fire trucks were called in from Hastings and the service's hazardous materials units were also sent to the scene.
Mr Nicholl said about 10 trucks and about 40 firefighters turned out.
Police closed off Pandora by placing roadblocks at Thames St off Pandora Rd and off Prebensen Drive where it leads into Severn St.
At the height of the fire flames stretched for about 60m along the top of the A-frame type storage building and palls of black smoke could be seen from as far as Taradale.
The northern side of Prebensen Drive filled with parked vehicles as their occupants stopped to watch. Flaming parts of the roof could be seen breaking away and sliding down the steep roof, leaving black smears.
Firefighters used extendable snorkel units to send water across the roofline and had the fire under control after about 25 minutes.
While most of the smoke billowed high across the Pandora area, it did leave what one automotive worker two streets away described as "a plasticky smell" in the air.
"But no, it wasn't that bad."
He said the building had had new clear-light plastic roofing put on at the start of the year.
"That's what was going up."
Some staff at neighbouring businesses also evacuated themselves from the immediate smoke zone.
Mr Richards said the office and production bagging areas were not affected.
"With a bit of ingenuity and flexibility we can continue to process orders.
"We're hopeful disruption will be minimal."
The fire was still being damped down four hours later and engineers were expected to enter the building today to make an accurate damage assessment.