One house has been destroyed and two others damaged in a fire in Newtownards.
A makeshift hut at a bonfire caught light early on Friday, spreading to a fence behind a number of homes at East Mount.
It then set two oil tanks ablaze, gutting one semi-detached house.
The Fire Service said the quick actions of firefighters saved two others from being destroyed. One firefighter suffered minor injuires.
He was treated at the scene by ambulance personnel.
The couple whose home was destroyed are due to return from a holiday in Turkey on Friday.
A neighbour said the bonfire had been built too close to the houses.
"At the back there's a green where they've been building the bonfire - have done for years up here - but obviously they've built it a little bit too close, stored the wood too close to the back of the house.
"It was ignited overnight and it hit the garden fence," he said.
"Last year they had to bring the fire trucks up to douse the houses because the flames were too close.
"You would think that something would be done as far as relocating the bonfire. Now this is the true sign in black and white that it was too close."
Meanwhile, the Fire Service has repeated warnings about the siting of bonfires after the house was destroyed in Newtownards.
NI Fire Service Group Commander John Denvir said that it was important that bonfires were well looked after.
He said that the majority of bonfires were well managed "but unfortunately you can see how quickly a bonfire which is allowed to get out of control can have devastating consequences".