A fire broke out inside the old Austins department store building in Derry city centre on Tuesday.
The fire started in a display unit and the incident is being described as “accidental ignition”.
There are no reports of any injuries.
Two teams from the Northland Road Northern Ireland Fire and Rescue Service (N.I.F.R.S.) station brought the fire under control and the incident had been dealt with shortly before midday.
The incident caused traffic disruption in the area.
Austins has been empty since the building closed its doors to the public in 2016.