A man has been hospitalised and a dog has died in a house fire.
Cornwall Fire and Rescue Service was called to the blaze on Cannon Hill, Liskeard just before 04:00 BST.
"One casualty has been taken to Derriford Hospital with smoke inhalation - unfortunately one dog did actually die in the fire," said incident commander Lee Griffin.
The blaze was put out by 09:00 and an investigation into its cause is under way.
The fire service said appliances from Callington, Looe, Lostwithiel, Saltash and Bodmin were called, with more than 50 firefighters at the scene.
Nearby residents were asked to keep their doors and windows closed due to the "large smoke plume".
The four-floor terraced property as well as neighbouring flats have suffered "significant damage", the fire service said.
"There's some smoke and water damage to adjacent properties, so unfortunately those people have got to be displaced, and also the people in the main house," Mr Griffin added.