UPDATE: One person is dead after two houses were destroyed by fire in Collie this morning.
The Arson Squad has confirmed the discovery of human remains inside one of the houses.
Det-Sgt Chris De Bruin said the remains were found at the Wittenoom Street property just before noon.
The identity of the deceased is yet to be established.
Colin Cluning was initially unaccounted for, but it is now believed his remains were found in the house.
The 65-year-old man's friends and family today paid tribute to Mr Cluning, who had lived in the house his entire life.
Mr Cluning - who lived alone in the house and is understood to have suffered from dementia - was a well-liked member of the Collie community.
"As a result of the investigation the remains of what is believed to be a human was located inside one of the houses,” Det-Sgt De Bruin said.
“At this point in time I don’t exactly know what part of the house the remains were found in because I’m told the damage was extensive."
Shocked neighbours said the retiree, who was in his home when the fire was reported just before 4am, had lived in Collie his entire life.
Det-Sgt De Bruin said Mr Cluning's family was told remains had been found.
The cause of the fire was not suspicious and would not be investigated as an arson incident, police said.
“We’re working to determine the cause of the fire," Det-Sgt De Bruin said.
Neighbour Michael Birkinshaw said the fire was overwhelming.
“You knew he was inside but you couldn’t have got in there anyway ... (the fire) was just too much,” Mr Birkinshaw said.
The second house destroyed was understood to have been occupied by a young couple.
“I’ve spoken to the (couple); they’ve lost everything except the keys to the cars,” Mr Birkinshaw said.
“Their house took about 10 minutes and it was gone.
"I believe the council is providing them with clothes and a place to stay.”
Det-Sgt De Bruin said the couple were “doing OK”.
Their evidence would be critical in the investigation, he said.
Emergency services praised Wittenoom Street residents for their quick thinking in warning residents of other houses while others rushed to help with garden hoses.
One such Good Samaritan was 44-year-old Trevor Tilbrook.
“I went down and had a look and came running back to the house to grab the hose,” Mr Tilbrook said.
“I started watering down the gutters of the third house. I couldn’t stand back and let it burn.”
The fire started at a house on Wittenoom Street just before 4am and quickly spread to a neighbouring house.
It took 20 firefighters about two hours to extinguish the fires.
A police spokesman said initially that a male resident from one of the houses was unaccounted for.
Emergency services checked the local hospital and other places in the area for the man.
It is believed no one else was injured during the blaze.
Police will prepare a report for the Coroner.