Preston firefighters were called to a city centre fire after a worrying 999 call suggested a person was still inside the building, say fire services.
Three pumps were sent to the incident which happened at around 6.30pm in a derelict building on Cannon Street.
Crews used breathing apparatus to thoroughly check the building to ensure that nobody was inside.
The fire was extinguished using a hose-reel.
The cause of the fire is unknown and nobody was injured during the incident.