Arsonists are believed to have started a fire which gutted a house in Callington in the early hours of yesterday.
Fire crews were called to the end-of-terrace house in Coronation Road at 5.30am after neighbours were alerted to the unfolding emergency.
The house, which is normally occupied by a family of four, was empty at the time.
Station manager Richard Gibbons, who is based at Bodmin, said crews who arrived on the scene found the house well alight.
"It was fully developed by the time the fire crews arrived," he said.
"We believe the fire started in the kitchen and was able to spread upstairs before the alarm was raised."
Mr Gibbons said there were fears that the blaze would spread and neighbours were ordered to evacuate.
There was a smoke alarm hard wired into the property, but Mr Gibbons said it was believed to have been de-activated.
He said their investigation had pinpointed arson as the most likely cause of the fire.
"It was a deliberate act of someone using a naked flame to ignite combustible materials in the kitchen," he said.
"The downstairs of the property was completely gutted by the fire and the upstairs was severely damaged."
