A senior fire officer has warned that a five-storey Primark building that was gutted in a blaze is at risk of collapsing.
The historic building in Belfast city centre was burnt out in a blaze that ripped through the flagship store on Tuesday.
A 45-metre exclusion zone remains in place as fire officers warned the severe structural damage could cause the old building to collapse.
Northern Ireland Fire and Rescue Service (NIFRS) area commander Aidan Jennings said structural engineers are currently working at the scene to establish the extent of the damage and whether the facade of the 331-year-old building can be saved.
"There is still a risk it could collapse and that's why we have the cordons in place," he said.
"At the facade of the building you can see the structural damage and the collapsed and twisted steel but we can't access that area because of risk of it collapsing."
Fire crews were called to the scene at 11am on Tuesday and were there within minutes.
Mr Jennings said the fire was extreme and has caused major damage and structural collapse on all five floors of the Primark store.
The building was undergoing renovations to add 30,000 sq ft in a multimillion-pound refurbishment.
Firefighters were able to save the extension and prevent the fire from spreading to the new part.
Emergency services will remain in place throughout the day and into the night.
The fire crews used water supplies from the nearby Lagan River to help extinguish the major blaze.
"It's very difficult conditions and the temperature is extreme," Mr Jennings added.
"On a number of occasions we had to withdraw fire crews from the concrete stairs due to the collapses inside the building causing heat.
"This has been very much a team effort, not just with fire crew but all agencies."
Firefighters are continuing to deal with hot spots and areas of rubble, stock and timber that are burning under the collapsed structures.
Mr Jennings also said that part of their investigation will look at whether there were sprinklers inside the building.
He added that the cause of the fire is not yet known.
A number of Primark staff and union representatives met with management at a hotel on Wednesday to discuss future plans.
Belfast city councillors also met with Primark officials.
Lord Mayor of Belfast Deirdre Hargey was among those who met officials.
Speaking afterwards, the Sinn Fein councillor said it was too early to say whether the facade of the historic building can be saved.
She added: "We also discussed keeping the city centre open for business. We all need to pull together and ensure we secure the site and get people back into work again."
The area that is closed off to the public includes a number of small independent businesses.
"We need to get them back up and running again," Ms Hargey added.
"It's been devastating - I've been speaking with the Primark staff. There's 360 staff and they are like a family so they're really impacted by this.
"It's a real sense of loss to them.
"We will look at all avenues to get this back up and running again or see whether Primark can relocate somewhere else to make sure the employees have employment.
"Firefighters have been working tirelessly around the clock and we have to give them their full support."
A Primark spokesman said: "Following yesterday's fire at our Bank Buildings store in Belfast, the welfare of our colleagues remains our most important concern and we are fully committed to supporting them during this difficult time.
"Our management team in Belfast are meeting their colleagues over the next few days to provide them with the necessary support and information.
"We are continuing to work with the relevant authorities to determine the cause of the fire.
"We would like to thank everyone for their amazing support during this very challenging time for all concerned."