Fire services have returned to another fire at the scene of a blaze they'd doused last night.
Firefighters attended two Petone house fires on Guy Fawkes' night but neither were thought to be fireworks related.
The owner of a Cuba St unit where a fire was put out last night returned to check on damage this morning and found smoke coming from the building at about 9am.
Two fire trucks attended both fires at the unit, and two men were evacuated from adjoining flats last night as a precaution.
Seaview station officer Ian Wright says investigators believe the fire was caused by an electrical fault.
Power had not been turned back on at the flat when the fire reignited, but it was likely a hidden hot spot behind the hot water cupboard had flared up again, he says.
"It can be very tricky, the fire can hide for a while, and then re-ignite when it gets a little bit more oxygen.
"We don't like to come back to a fire that's restarted again, so we've had to remove a whole lot more of the house to make sure it doesn't start again."
The father of the owner, who wished to remain unnamed, said the fire had destroyed the hot water cupboard, but most of the rest of the damage was from smoke.
"She popped out to watch the fireworks on the foreshore last night, and when she came back she found the fire brigade here.
"She's obviously very upset."
Fire services were first called to the Cuba St address just before 9:45 on Guy Fawkes night, but received another call within minutes to a second home in flames, on The Esplanade.
Fire communications say the second fire was well involved and was attended by four fire trucks and two special response units.
Owners Katie Pearce and Tom Rough arrived home with a flatmate to find fire fighters extinguishing the last of the flames.
Investigators have told them they believe the fire started in a rubbish bag at the back of the house.
"It doesn't look like it was fireworks, just bad luck," Ms Pearce says.
"It was just from a rubbish bag that's smouldered in the sun over Sunday and Monday with paper towels and oils in, and then it's completely gone up the back of the house."
The building will need extensive repairs. A spare room at the back of the house was completely gutted, the neighbouring bathroom was badly damaged and the fire had begun to spread to other rooms when it was put out.
"It was pretty horrific. Our stuff's had it. It's been a long night," Ms Pearce said.
"I guess we just deal with it, it's only stuff, we're just lucky we weren't home."
The fire service and police at the scene had been "amazing", she says.
Both homes were insured.
Central fire communications shift manager David Meikle said fire fighters responded to about 40 calls across the central and lower North Island between 6pm and 12am last night, most sparked by fireworks.
- Hutt News