Fire crews have said an 89-year-old disabled man and his son are "lucky to be alive" after a blaze swept through their home in Exeter.
The fire broke-out in the early hours of Saturday at the terraced property in Well Street near the city centre.
Devon and Somerset Fire Service received several calls from students living nearby after the fire took hold at around 1.45am.
The elderly man and his 58-year-old son were found by firefighters at the back of their three-storey property.
They were treated for the effects of smoke inhalation before being put up at a nearby hotel.
Firefighters had to deal with gas cylinders in one room before the fire was brought under control by 3.30am.
They were assisted at the scene by Devon and Cornwall Police.
Three quarters of the property was severely damaged by fire, and the remainder was damaged by heat and smoke.
Occupants of adjacent and nearby properties were temporarily evacuated as a precaution.
The fire is understood to have started when furniture was set alight by embers from an open fire.
A police spokesman said: "The occupants tried their best to put out the blaze but it got out of their control."
"It's a very unfortunate thing to have happened just before Christmas."
Five fire engines attended the scene and used two hoses to extinguish the flames.
Gas engineers were called to deal with a suspected suspected ruptured gas main inside the property.
An investigation into the cause of the fire by police and fire officers confirmed it was accidental.
