Firefighters from Bispham and Fleetwood were called to a house fire in Thornton.
The blaze started around 3.30am this morning in the back bedroom of a property in Mayfield Avenue before spreading across the first floor and roof space.
Three people were evacuated from the building before two fire engines from Fleetwood and one from Bispham arrived at the scene.
Fleetwood crew manager Kevin Warwick said: “As soon as we turned into the street it was obvious this was a serious incident. It was confirmed at an early stage that nobody was in the property, which was a relief as the fire was extremely intense and had spread across the whole of the first floor. The back windows had failed and smoke and fire was issuing from two upstairs windows.
“It took 20 minutes to bring the blaze under control. On another day these circumstances may have resulted in serious injury or worse.”
Investigations are continuing into the cause of the blaze, but it is believed it was started accidentally.