A fire in Hobart's southern suburbs on Saturday came "within metres" of torching 15 homes, the Tasmania Fire Service (TFS) says.
The TFS investigation later determined the cause was accidental, starting when the metal blade of a brush cutter came into contact with rocks and produced sparks that ignited nearby vegetation.
"Despite attempts made by the person to extinguish the fire, due to the dry fuels and a steep slope, it spread rapidly and emergency services were called," the TFS on Sunday said.
The blaze started at Proctors Road, Dynnyrne, just after 2:00pm on Saturday and quickly made its way up the hill towards Mt Nelson.
An evacuation order was issued by the TFS just before 3:30 pm but was downgraded to a watch and act alert 12 minutes later.
By 6:00pm, it had been downgraded further to advice level.
Fire crews from six brigades and four aircraft were deployed to fight the blaze, which is currently about two hectares in size.
TFS chief officer Dermot Barry said a quick response from both air and ground crews stopped the fire from destroying any homes.
"They managed to pull the fire up before it got into those homes and now they're working to extinguish it completely and make the area safe," he said.
"At the moment, the fire is contained but it's certainly not extinguished. You can still see there's a number of helicopters up and working. They're looking for hotspots and helping contain it."
Ground crews will head out onto the fireground overnight and ensure the fire is completely extinguished.
Mr Barry said a previous fuel reduction burn in the area also helped to stop the fire's progress.
"It's a fantastic result," he said.
"I think part of it is people had prepared their homes as well. They had their plans in place, probably had cleared around their homes, those sorts of things."
Emily Garrett and Cato Wastell were driving through Sandy Bay when they saw flames as large as nearby trees and drove to Dynnyrne Road for a closer look.
"The flames were huge, it was crazy, thank God they've got it under control now," Mr Wastell said.
"It was really scary, even when we were so far away."
Dynnyrne resident Dermott Fitzpatrick was in his garden when he heard helicopters in the air.
"It felt like it was a warzone with all the noise of that going over," he said.
He praised the response from emergency services.
"They're on top of it straight away," he said.
"You come out and see they've got the fire under control.
"It could have been a dangerous situation but it's all turned out good."