Emergency services rushed to a building in central Wellington after an electrical fire was discovered shortly after 9am today.
Thorndon senior station officer Clarke Townsley said lack of staff meant firefighters could not enter the building as soon as they would have liked to track down the source of the fire.
When they did enter, they found an electrical board was ablaze, and put it out, he said.
Firefighters had been "anxious" to begin with as the building on Manners St is five storeys high, and Wellington only has appliances that can reach about three storeys, Townsley said.
On Monday most of the country's fire stations were left without access to a high ladder appliance, after Christchurch's 32m ladder appliance was sent for servicing and Wellington's last high ladder appliance broke down.
It meant no high ladder appliances were available between Hamilton and Dunedin. The appliances can reach about 8-10 storeys.
Wellington stations are currently borrowing a 17m appliance.
The New Zealand Professional Fire Fighters Union earlier said the country was in the midst of a "fire crisis" with dire staffing issues.
The union and Fire and Emergency NZ said they were currently working on a process to "re-engage constructively in collective bargaining".
"A mutually agreed third party will be engaged to support and assist this re-engagement," they said.
"The industrial action currently under way remains in place, but this will not impact our career firefighters' ability to respond to emergency incidents."
Both parties have agreed not to engage in media interviews about the issues to be progressed through the collective bargaining process.