Fire crews fought a blaze at a flat in Leigh after it broke out in the property's outhouse.
The fire, which was inside a two-storey flat on Conway Close, was reported at around 10.30pm last night.
Three fine engines attended the scene to find that flames had started in an outhouse before spreading to the main building.
Police and an ambulance also attended the scene as firefighters searched the flames to find any occupants inside.
No one was found in the building and there were no casualties, but firefighters said that the flames had fractured a gas main and that the situation was made "very dangerous" for crews inside the building.
The gas board turned up to isolate the mains to prevent an explosion.
The flat has been severely smoke damaged.
Fire officers are investigating the incident to determine if it was started "maliciously" or by accident.